\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/HalfBloodPrince\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/332453/avatar/a1a516d280a7dbef.jpg'/> </a>\n <div><a href=\"/profile/HalfBloodPrince\" title=\"Expert HalfBloodPrince\" class=\"rated-user user-blue\">HalfBloodPrince</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/21/2016 18:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-301587\" href=\"?#comment-301587\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"301587\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"301587\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"332453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-301587\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could a top-down approach be used for div1 B/div2 D? I tried a top down approach but I am not able to memoize it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-301587 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-301587 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-301587\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310750\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/red_dust\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/417513/avatar/d7a2f654b2949853.jpg'/> </a>\n <div><a href=\"/profile/red_dust\" title=\"Expert red_dust\" class=\"rated-user user-blue\">red_dust</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/19/2016 11:02\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310750\" href=\"?#comment-310750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"417513\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div A/Div2 C Escape from Stones the algorithm is easy to understand if someone explains it,</p><p>but I don't understand how this solution came to be, which trail of thought led to this solution.</p><p>can someone please explain it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"331390\" commentParentId=\"310750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marlonbymendes\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/358576/avatar/a4da054df60816b9.jpg'/> </a>\n <div><a href=\"/profile/marlonbymendes\" title=\"Expert marlonbymendes\" class=\"rated-user user-blue\">marlonbymendes</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/18/2016 00:15\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-331390\" href=\"?#comment-331390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-310750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"331390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"358576\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-331390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Read my comment below.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-331390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-331390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-331390\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"331388\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marlonbymendes\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/358576/avatar/a4da054df60816b9.jpg'/> </a>\n <div><a href=\"/profile/marlonbymendes\" title=\"Expert marlonbymendes\" class=\"rated-user user-blue\">marlonbymendes</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/18/2016 00:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-331388\" href=\"?#comment-331388\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"331388\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"358576\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-331388\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think editorial nor comments explanation on solution <a href=\"/contest/264/problem/A\" title=\"Codeforces Round 162 (Div. 1)\">264A - Escape from Stones</a> are intuitive so I'll try to explain how I came up with a solution. </p><p>You can visualize the problem as a binary tree. Each node is responsable for a interval <strong>[a, b]</strong>. Starting from the root, responsable for <strong>[0, 1]</strong>, if you go left then root will have a left child responsable for interval <strong>[0, 1 / 2]</strong>. Since you're a left child, last time the stone fell on position 1 / 2, the end point of the interval.</p><p>Note that from that child, it doesn't matter if you go left or right: the stone will never fall on a position bigger than 1 / 2 (the end point). The ideia is: since a stone always fall on the midpoint <strong>(a + b) / 2</strong> of the lower and end points, it can never fall after the endpoint. In fact, the stone must fall infinitely many times to the right to reach that endpoint. So, we were on a node [0, 1], the stone fell and we jumped to the left, creating a left child [0, 1 / 2] and we now know that there is no way the stone will every fall to a position > 1 / 2. This means that in the final solution, the current node [0, 1 / 2] will come AFTER all nodes (descendents) that come after this one.</p><p>If we jumped to the right instead, creating a right child responsable for interval [1 / 2, 1] we can show the same way that the stone will never fall before the starting point 1 / 2. This means that the current node will com BEFORE all nodes (descendents) that come after this one, since we know that the stone can't fall on a postion < 1 / 2 from now on.</p><p>This is an algorithm: if in the i'th stone we jumped to the left, we now that stone i will become AFTER all next stones. If we jumped right, stone i will become BEFORE all next stones.</p><p>Code: <a href=\"/contest/264/submission/23071895\" title=\"Submission 23071895 by marlonbymendes\">23071895</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-331388 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-331388 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-331388\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"386173\" commentParentId=\"331388\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ameyanator\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/464121/avatar/e34f7dc2b59a7b4c.jpg'/> </a>\n <div><a href=\"/profile/ameyanator\" title=\"Specialist ameyanator\" class=\"rated-user user-cyan\">ameyanator</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/18/2017 10:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-386173\" href=\"?#comment-386173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-331388\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"386173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"464121\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-386173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Awesome explanation thanks! :')</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-386173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-386173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-386173\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360590\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/the_an0nym0us\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/303591/avatar/41fc9495b1ea2f27.jpg'/> </a>\n <div><a href=\"/profile/the_an0nym0us\" title=\"Specialist the_an0nym0us\" class=\"rated-user user-cyan\">the_an0nym0us</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/17/2017 08:56\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360590\" href=\"?#comment-360590\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360590\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"303591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360590\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Strange! My C++ code got accepted with printf but got TLE with cout. This is too harsh</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360590 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360590 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360590\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360690\" commentParentId=\"360590\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/559880/avatar/fd0565aa541e0d1.jpg'/> </a>\n <div><a href=\"/profile/Guy\" title=\"Candidate Master Guy\" class=\"rated-user user-violet\">Guy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/18/2017 10:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360690\" href=\"?#comment-360690\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-360590\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"360690\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"360690\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"559880\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360690\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>printf is faster than cout. if u want to use cout its better type ios::sync_with_stdio(false),cin.tie(0),cout.tie(0); in your code this make cout fast</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360690 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360690 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360690\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"365999\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akhi29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207626/avatar/c39a3ca998f53094.jpg'/> </a>\n <div><a href=\"/profile/akhi29\" title=\"Pupil akhi29\" class=\"rated-user user-green\">akhi29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2017 01:33\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-365999\" href=\"?#comment-365999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"365999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"365999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207626\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-365999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm unable to solve Escape from Stones in java. In spite of using fast io, it always gives me a TLE now matter how much i optimize it <a href=\"//codeforces.com/contest/264/submission/27712057\">sol</a> did anyone get it AC in java?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-365999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-365999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-365999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"385333\" commentParentId=\"365999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zodiacleo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/zodiacleo\" title=\"Pupil zodiacleo\" class=\"rated-user user-green\">zodiacleo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2017 11:29\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-385333\" href=\"?#comment-385333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-365999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"385333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"145879\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-385333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi <a class=\"rated-user user-green\" href=\"/profile/akhi29\" title=\"Pupil akhi29\">akhi29</a><br />Two points-<br />1. Try to use <code>StringBuilder</code> (popular practice among Java user's) instead of directly printing to the output console.<br />2. When you call, <code>close()</code> of <code>PrintStream</code>, it isn't obliged to flush your output to the console. You need to call <code>flush()</code> explicitly to ensure that the data, if present in the buffer is flushed to the output console. You can refer the modified submission <a href=\"/contest/264/submission/30322735\" title=\"Submission 30322735 by zodiacleo\">30322735</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-385333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-385333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-385333\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587566\" commentParentId=\"385333\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akhi29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207626/avatar/c39a3ca998f53094.jpg'/> </a>\n <div><a href=\"/profile/akhi29\" title=\"Pupil akhi29\" class=\"rated-user user-green\">akhi29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 01:45\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587566\" href=\"?#comment-587566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-385333\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207626\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks zodiacleo</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"379370\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Target2018\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/295556/avatar/f6fe0b640b7fee7.jpg'/> </a>\n <div><a href=\"/profile/Target2018\" title=\"Newbie Target2018\" class=\"rated-user user-gray\">Target2018</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/18/2017 18:55\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-379370\" href=\"?#comment-379370\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"379370\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"295556\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-379370\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In <a href=\"//codeforces.com/contest/265/problem/C\">DIV 2 C</a> I took 2 variables hi = 1 and lo = 0, if character is 'l' then I just change hi = (hi + lo) / 2 otherwise lo = (hi + lo) / 2 and mapped the value, sort them and print them, but got WA on Testcase 11, could you please tell me what is I'm missing?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-379370 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-379370 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-379370\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"384618\" commentParentId=\"379370\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bibhuti\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/561745/avatar/eb1f97e82517cf9e.jpg'/> </a>\n <div><a href=\"/profile/Bibhuti\" title=\"Specialist Bibhuti\" class=\"rated-user user-cyan\">Bibhuti</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/07/2017 19:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-384618\" href=\"?#comment-384618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-379370\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"384618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"561745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-384618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I hope it may be because of the precision problem. I am also facing the same and below is my solution</p><p><a href=\"/contest/264/submission/30185936\" title=\"Submission 30185936 by Bibhuti\">30185936</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-384618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-384618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-384618\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"396488\" commentParentId=\"384618\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/neroond\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/375945/avatar/2a26526cf4420757.jpg'/> </a>\n <div><a href=\"/profile/neroond\" title=\"Expert neroond\" class=\"rated-user user-blue\">neroond</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/21/2017 13:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-396488\" href=\"?#comment-396488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-384618\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"396488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"375945\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-396488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in DIV2 D what will be answer in case 5 : 2 4 8 6 9. My solution that got AC. outputs 5, but how? 8 is bigger than 6 they can't form a sequence </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-396488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-396488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-396488\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"411637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sabertooth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/547698/avatar/2106fe4acab8cfe4.jpg'/> </a>\n <div><a href=\"/profile/sabertooth\" title=\"Specialist sabertooth\" class=\"rated-user user-cyan\">sabertooth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2018 07:14\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-411637\" href=\"?#comment-411637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"411637\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"411637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"547698\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-411637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In <strong>Div 1 A</strong> Stones falls in 'k' position and print the stone position from left</p><p>I calculated 'k' and 'd' as k=(X+Y)/2 and d=(Y-X)/2 And if 'l' then x-=d otherwise y+=d. then sorted the array which contains 'k' s value and its position no. but my implementation isn't matching with the test case..</p><p>Did I misunderstood the ques or my idea is wrong?</p><p><a href=\"https://paste.ubuntu.com/26503881/\">CODE</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-411637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-411637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-411637\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"453240\" commentParentId=\"411637\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wallcrawler\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/446649/avatar/28b029f94566d9b0.jpg'/> </a>\n <div><a href=\"/profile/wallcrawler\" title=\"Expert wallcrawler\" class=\"rated-user user-blue\">wallcrawler</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/22/2018 10:35\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-453240\" href=\"?#comment-453240\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-411637\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"453240\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"446649\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-453240\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The thing is that, suppose you only go left then it means that the stones would be at 1/2,1/4,1/8,...till 1/(2^(10^6)) (considering maximum length of the string) which can't be stored in the float value.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-453240 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-453240 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-453240\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469926\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/umangahuja1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/480801/avatar/6a0f8d27102d0ec0.jpg'/> </a>\n <div><a href=\"/profile/umangahuja1\" title=\"Expert umangahuja1\" class=\"rated-user user-blue\">umangahuja1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 11:09\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469926\" href=\"?#comment-469926\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"469926\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"480801\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469926\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For those facing TLE in the problem Div1 A (Div2 C Escape from Stones) in C++ even with <code>O(N)</code> time complexity the reason can be <code>endl vs '\\n'</code>.</p><p><code>'\\n</code>' inserts a new line to the output stream while</p><p><code>endl</code> inserts a new line as well as flushes the output stream.</p><p>So using <code>'\\n'</code>can solve the TLE issue.</p><p>Also you can use fast IO with cin/cout too instead of using scanf/printf by adding these lines in your code.</p><p><code>ios::sync_with_stdio(false);</code></p><p><code>cin.tie(0);</code></p><p><code>cout.tie(0);</code></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469926 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469926 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469926\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"494267\" commentParentId=\"469926\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SohrabRoohi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SohrabRoohi\" title=\"Specialist SohrabRoohi\" class=\"rated-user user-cyan\">SohrabRoohi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/22/2019 01:54\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-494267\" href=\"?#comment-494267\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-469926\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"494267\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"620634\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-494267\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Believe it or not this actually solved the problem for me. I was using a linked list and basically pushing to the front and back and was confused how I was getting TLE with 1,000,000 O(1) operations. I ended up writing my own code for a linked list and still failed case 31, changing the endl to \\n made it accepted. This made it go from 2000 ms TLE to 233 ms, thank you for your post.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-494267 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-494267 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-494267\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512701\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pseudocoder10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/pseudocoder10\" title=\"Master pseudocoder10\" class=\"rated-user user-orange\">pseudocoder10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2019 15:13\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512701\" href=\"?#comment-512701\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"512701\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"512701\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"786409\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512701\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved div1A using a binary tree, if character is l then i add to the left of parent node otherwise i add to the right, then an inorder traversal will give the answer but im getting TLE at testcase 31 idk why since my code is implemented in O(n) complexity. My solution(<a href=\"https://codeforces.com/contest/264/submission/54413614\">https://codeforces.com/contest/264/submission/54413614</a>)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512701 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512701 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512701\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"553043\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wolfie.\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/889894/avatar/b1389c1ceb58933b.jpg'/> </a>\n <div><a href=\"/profile/wolfie.\" title=\"Expert wolfie.\" class=\"rated-user user-blue\">wolfie.</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2019 17:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-553043\" href=\"?#comment-553043\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"553043\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"553043\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"889894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-553043\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Something is wrong with the testing of the question Div 1(A)/ Div2(C) . Got 2 TLE's on a O(n) solution [Test Case 31] , changed endl and to '\\n' and then got runtime error on test 41. </p><p>TLE — <a href=\"https://codeforces.com/contest/265/submission/63245660\">https://codeforces.com/contest/265/submission/63245660</a> Runtime Error — <a href=\"https://codeforces.com/contest/265/submission/63246396\">https://codeforces.com/contest/265/submission/63246396</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-553043 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-553043 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-553043\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621308\" commentParentId=\"553043\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/UNOwen98\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/UNOwen98\" title=\"Expert UNOwen98\" class=\"rated-user user-blue\">UNOwen98</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 09:56\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621308\" href=\"?#comment-621308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-553043\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1254135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am facing the same problem. Were you able to fix it ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621308\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621403\" commentParentId=\"621308\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wolfie.\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/889894/avatar/b1389c1ceb58933b.jpg'/> </a>\n <div><a href=\"/profile/wolfie.\" title=\"Expert wolfie.\" class=\"rated-user user-blue\">wolfie.</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621403\" href=\"?#comment-621403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-621308\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"889894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, i kept on getting runtime error with that approach.. so i changed my implementation a little bit, and it got accepted. <a href=\"https://codeforces.com/contest/265/submission/63246871\">Accepted Solution.</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621435\" commentParentId=\"621403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/UNOwen98\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/UNOwen98\" title=\"Expert UNOwen98\" class=\"rated-user user-blue\">UNOwen98</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 13:39\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621435\" href=\"?#comment-621435\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-621403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621435\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"1254135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621435\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I had to do this too. I guess the problem was caused because the second loop ( which is being run backwards ) was trying to access some invalid memory. The problems gets fixed when the array is reversed and loop is run forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621435 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621435 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621435\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"664098\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iabhishek15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1226114/avatar/6ce33a9f7d454deb.jpg'/> </a>\n <div><a href=\"/profile/iabhishek15\" title=\"Expert iabhishek15\" class=\"rated-user user-blue\">iabhishek15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2020 19:31\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-664098\" href=\"?#comment-664098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"664098\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"664098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1226114\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-664098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an another approach for div1B. for each number check the maxm times a divisor has occurred from all the divisors of a number and then increase the maxm by 1 and iterate again and update all the divisors</p><p>code <a href=\"/contest/264/submission/87253298\" title=\"Submission 87253298 by iabhishek15\">87253298</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-664098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-664098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-664098\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1035696\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ahmed_ElGendy56\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2725312/avatar/e34f70ed817bafea.jpg'/> </a>\n <div><a href=\"/profile/Ahmed_ElGendy56\" title=\"Pupil Ahmed_ElGendy56\" class=\"rated-user user-green\">Ahmed_ElGendy56</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/07/2023 19:42\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1035696\" href=\"?#comment-1035696\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1035696\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-7\"\r\n data-commentUserId=\"2725312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1035696\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you are using C++ for solving (Div1 A / Div2 C Escape from Stones) and got a TLE error on the 31st test you have to be sure you are using ("\\n") instead of (endl) because (endl) takes more time for flushing.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1035696 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1035696 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1035696\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046784\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/oishi_161\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2006012/avatar/8428423d6c055dae.jpg'/> </a>\n <div><a href=\"/profile/oishi_161\" title=\"Newbie oishi_161\" class=\"rated-user user-gray\">oishi_161</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 11:18\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046784\" href=\"?#comment-1046784\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046784\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2006012\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046784\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem div2 B in more detail?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046784 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1046784 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1046784\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046792\" commentParentId=\"1046784\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SummerSky\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/419016/avatar/8ddf3c5c2dc6bf44.jpg'/> </a>\n <div><a href=\"/profile/SummerSky\" title=\"Expert SummerSky\" class=\"rated-user user-blue\">SummerSky</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 11:36\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046792\" href=\"?#comment-1046792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-1046784\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"419016\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Note that we can only move to the next tree, but not to the previous one. So, to eat all the nuts, we must start from the first tree and visit one by one until we reach the final one. When we are on the top of some tree-i (because we must go to the top to eat that nut), and eat the nut, then we should move to the next tree. If next tree has lower height, we have to move down to the same height and then jump (to save time). Otherwise, we can directly jump to the next tree (also to save time). </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1046792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1046792\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046818\" commentParentId=\"1046792\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/oishi_161\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2006012/avatar/8428423d6c055dae.jpg'/> </a>\n <div><a href=\"/profile/oishi_161\" title=\"Newbie oishi_161\" class=\"rated-user user-gray\">oishi_161</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 12:46\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046818\" href=\"?#comment-1046818\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-1046792\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046818\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2006012\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046818\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for your help.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046818 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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Escape from Stones"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Escape from Stones</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Squirrel Liss lived in a forest peacefully, but unexpected trouble happens. Stones fall from a mountain. Initially Squirrel Liss occupies an interval <span class=\"tex-span\">[0, 1]</span>. Next, <span class=\"tex-span\"><i>n</i></span> stones will fall and Liss will escape from the stones. The stones are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> in order.</p><p>The stones always fall to the center of Liss's interval. When Liss occupies the interval <span class=\"tex-span\">[<i>k</i> - <i>d</i>, <i>k</i> + <i>d</i>]</span> and a stone falls to <span class=\"tex-span\"><i>k</i></span>, she will escape to the left or to the right. If she escapes to the left, her new interval will be <span class=\"tex-span\">[<i>k</i> - <i>d</i>, <i>k</i>]</span>. If she escapes to the right, her new interval will be <span class=\"tex-span\">[<i>k</i>, <i>k</i> + <i>d</i>]</span>.</p><p>You are given a string <span class=\"tex-span\"><i>s</i></span> of length <span class=\"tex-span\"><i>n</i></span>. If the <span class=\"tex-span\"><i>i</i></span>-th character of <span class=\"tex-span\"><i>s</i></span> is \"<span class=\"tex-font-style-tt\">l</span>\" or \"<span class=\"tex-font-style-tt\">r</span>\", when the <span class=\"tex-span\"><i>i</i></span>-th stone falls Liss will escape to the left or to the right, respectively. Find the sequence of stones' numbers from left to right after all the <span class=\"tex-span\"><i>n</i></span> stones falls.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input consists of only one line. The only line contains the string <span class=\"tex-span\"><i>s</i></span> (<span class=\"tex-span\">1 ≤ |<i>s</i>| ≤ 10<sup class=\"upper-index\">6</sup></span>). Each character in <span class=\"tex-span\"><i>s</i></span> will be either \"<span class=\"tex-font-style-tt\">l</span>\" or \"<span class=\"tex-font-style-tt\">r</span>\".</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>n</i></span> lines — on the <span class=\"tex-span\"><i>i</i></span>-th line you should print the <span class=\"tex-span\"><i>i</i></span>-th stone's number from the left.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>llrlr<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>5<br/>4<br/>2<br/>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>rrlll<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>2<br/>5<br/>4<br/>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>lrlrr<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/>4<br/>5<br/>3<br/>1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, the positions of stones 1, 2, 3, 4, 5 will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58fdb5684df807bfcb705a9da9ce175613362b7d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>, respectively. So you should print the sequence: 3, 5, 4, 2, 1.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"048630aef17fae3c489a51cf333b68ad\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"19843d15aee6a49b49ab812b3433503e5e4f1193\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_c6ee82ef5f659093910705ace0c2966eb21daddd\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Escape from Stones</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Squirrel Liss lived in a forest peacefully, but unexpected trouble happens. Stones fall from a mountain. Initially Squirrel Liss occupies an interval <span class=\"tex-span\">[0, 1]</span>. Next, <span class=\"tex-span\"><i>n</i></span> stones will fall and Liss will escape from the stones. The stones are numbered from 1 to <span class=\"tex-span\"><i>n</i></span> in order.</p><p>The stones always fall to the center of Liss's interval. When Liss occupies the interval <span class=\"tex-span\">[<i>k</i> - <i>d</i>, <i>k</i> + <i>d</i>]</span> and a stone falls to <span class=\"tex-span\"><i>k</i></span>, she will escape to the left or to the right. If she escapes to the left, her new interval will be <span class=\"tex-span\">[<i>k</i> - <i>d</i>, <i>k</i>]</span>. If she escapes to the right, her new interval will be <span class=\"tex-span\">[<i>k</i>, <i>k</i> + <i>d</i>]</span>.</p><p>You are given a string <span class=\"tex-span\"><i>s</i></span> of length <span class=\"tex-span\"><i>n</i></span>. If the <span class=\"tex-span\"><i>i</i></span>-th character of <span class=\"tex-span\"><i>s</i></span> is "<span class=\"tex-font-style-tt\">l</span>" or "<span class=\"tex-font-style-tt\">r</span>", when the <span class=\"tex-span\"><i>i</i></span>-th stone falls Liss will escape to the left or to the right, respectively. Find the sequence of stones' numbers from left to right after all the <span class=\"tex-span\"><i>n</i></span> stones falls.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input consists of only one line. The only line contains the string <span class=\"tex-span\"><i>s</i></span> (<span class=\"tex-span\">1 ≤ |<i>s</i>| ≤ 10<sup class=\"upper-index\">6</sup></span>). Each character in <span class=\"tex-span\"><i>s</i></span> will be either "<span class=\"tex-font-style-tt\">l</span>" or "<span class=\"tex-font-style-tt\">r</span>".</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>n</i></span> lines — on the <span class=\"tex-span\"><i>i</i></span>-th line you should print the <span class=\"tex-span\"><i>i</i></span>-th stone's number from the left.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>llrlr<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />5<br />4<br />2<br />1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>rrlll<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />2<br />5<br />4<br />3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>lrlrr<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br />4<br />5<br />3<br />1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, the positions of stones 1, 2, 3, 4, 5 will be <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/58fdb5684df807bfcb705a9da9ce175613362b7d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, respectively. 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:45</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4298c77d77d8d2562e182e69f443373f'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final 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style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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user-legendary\"><span class=\"legendary-user-first-letter\">r</span>ng_58</a>,\r\n <span class=\"format-humantime\" title=\"Jan/21/2013 18:21\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"//codeforces.com/problemset/problem/265/A\">Div2 A Colorful Stones (Simplified Edition)</a> (Author: <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>)</h4><p>In this problem you just need to implement what is written in the statement. Make a variable that holds the position of Liss, and simulate the instructions one by one.</p><h4><a href=\"//codeforces.com/problemset/problem/265/B\">Div2 B Roadside Trees (Simplified Edition)</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/snuke\" title=\"Expert snuke\">snuke</a>)</h4><p>The optimal path of Liss is as follows: First she starts from the root of tree 1. Walk up the tree to the top and eat a nut. Walk down to the height <span class=\"tex-span\"><i>min</i>(<i>h</i><sub class=\"lower-index\">1</sub>, <i>h</i><sub class=\"lower-index\">2</sub>)</span>. Jump to the tree 2. Walk up the tree to the top and eat a nut. Walk down to the height <span class=\"tex-span\"><i>min</i>(<i>h</i><sub class=\"lower-index\">2</sub>, <i>h</i><sub class=\"lower-index\">3</sub>)</span>, <span class=\"tex-span\">...</span> and so on.</p><h4><a href=\"//codeforces.com/problemset/problem/264/A\">Div1 A / Div2 C Escape from Stones</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/DEGwer\" title=\"Expert DEGwer\">DEGwer</a>)</h4><p>In this problem, there are many simple algorithms which works in <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. One of them (which I intended) is following:</p><p>You should prepare 2 vectors. If <span class=\"tex-span\"><i>s</i>[<i>i</i>] = '<i>l</i>'</span>, you should push i to the first vector, and if <span class=\"tex-span\"><i>s</i>[<i>i</i>] = '<i>r</i>'</span>, you should push i to the second vector. Finally, you should print the integers in the second vector by default order, after that, you should print the integers in the first vector in the reverse order.</p><p>This algorithm works because if Liss divides an interval into two intervals <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> and she enters <span class=\"tex-span\"><i>A</i></span>, she will never enter <span class=\"tex-span\"><i>B</i></span>.</p><h4><a href=\"//codeforces.com/problemset/problem/264/B\">Div1 B / Div2 D Good Sequences</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/DEGwer\" title=\"Expert DEGwer\">DEGwer</a>)</h4><p>The main idea is DP. Let's define <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> as the maximal value of the length of the good sequence whose last element is <span class=\"tex-span\"><i>x</i></span>, and define <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> as the (maximal value of <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> where <span class=\"tex-span\"><i>x</i></span> is divisible by <span class=\"tex-span\"><i>i</i></span>).</p><p>You should calculate <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> in the increasing order of x. The value of <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> is (maximal value of <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> where <span class=\"tex-span\"><i>i</i></span> is a divisor of <span class=\"tex-span\"><i>x</i></span>) + 1. After you calculate <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span>, for each divisor <span class=\"tex-span\"><i>i</i></span> of <span class=\"tex-span\"><i>x</i></span>, you should update <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> too.</p><p>This algorithm works in <span class=\"tex-span\"><i>O</i>(<i>nlogn</i>)</span> because the sum of the number of the divisor from 1 to <span class=\"tex-span\"><i>n</i></span> is <span class=\"tex-span\"><i>O</i>(<i>nlogn</i>)</span>.</p><p>Note that there is a corner case. When the set is <span class=\"tex-span\">{1}</span>, you should output 1.</p><h4><a href=\"//codeforces.com/problemset/problem/264/C\">Div1 C / Div2 E Choosing Balls</a> (Author: <a class=\"rated-user user-orange\" href=\"/profile/hogloid\" title=\"Master hogloid\">hogloid</a>)</h4><p>There are many <span class=\"tex-span\"><i>O</i>(<i>Q</i> * <i>N</i> * <i>logN</i>)</span> solutions using segment trees or other data structures, but probably they will get time limit exceeded.</p><p>We can solve each query independently. First, let's consider the following DP algorithm.</p><p><span class=\"tex-span\"><i>dp</i>[<i>c</i>]</span> := the maximal value of a sequence whose last ball's color is <span class=\"tex-span\"><i>c</i></span></p><p>For each ball <span class=\"tex-span\"><i>i</i></span>, we want to update the array. Let the <span class=\"tex-span\"><i>i</i></span>-th ball's color be <span class=\"tex-span\"><i>col</i>[<i>i</i>]</span>, the <span class=\"tex-span\"><i>i</i></span>-th ball's value be <span class=\"tex-span\"><i>val</i>[<i>i</i>]</span>, and the maximal value of dp array other than <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> be <span class=\"tex-span\"><i>otherMAX</i></span>. We can update the value of <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> to <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]] + <i>val</i>[<i>i</i>] × <i>a</i></span> or <span class=\"tex-span\"><i>otherMAX</i> + <i>val</i>[<i>i</i>] × <i>b</i></span>. Here, we only need to know <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> and <span class=\"tex-span\"><i>otherMAX</i></span>. If we remember the biggest two values of <span class=\"tex-span\"><i>dp</i></span> array in that time and their indexes in the array, <span class=\"tex-span\"><i>otherMAX</i></span> can be calculated using the biggest two values, which always include maximal values of dp array other than any particular color.</p><p>Since the values of dp array don't decrease, we can update the biggest two values in <span class=\"tex-span\"><i>O</i>(1)</span>. Finally, the answer for the query is the maximal value of <span class=\"tex-span\"><i>dp</i></span> array.</p><p>The complexity of the described algorithm is <span class=\"tex-span\"><i>O</i>(<i>QN</i>)</span>.</p><h4><a href=\"//codeforces.com/problemset/problem/264/D\">Div1 D Colorful Stones</a> (Author: <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>)</h4><p>First, let's consider a simpler version of the problem: You are given a start state and a goal state. Check whether the goal state is reachable from the start state.</p><p>Define <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span>, <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>D</i></span> as in the picture below, and let <span class=\"tex-span\"><i>I</i></span> be the string of your instructions. <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are substrings of <span class=\"tex-span\"><i>s</i></span>, and <span class=\"tex-span\"><i>C</i></span> and <span class=\"tex-span\"><i>D</i></span> are substrings of <span class=\"tex-span\"><i>t</i></span>.</p><p><img alt=\" \" src=\"https://assets.codeforces.com/images/162/CF162D1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>It is possible to reach the goal state from the start state if there exists an instruction <span class=\"tex-span\"><i>I</i></span> such that:</p> <ul> <li>1 <span class=\"tex-span\"><i>A</i></span> is a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>2 <span class=\"tex-span\"><i>B</i></span> is not a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>3 <span class=\"tex-span\"><i>C</i></span> is a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>4 <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> </ul><p>So we want to check if such string <span class=\"tex-span\"><i>I</i></span> exists. (string <span class=\"tex-span\"><i>s</i>1</span> is called a subsequence of <span class=\"tex-span\"><i>s</i>2</span> if it is possible to get <span class=\"tex-span\"><i>s</i>2</span> by removing some characters of <span class=\"tex-span\"><i>s</i>1</span>)</p><p>There are some obvious "NO" cases. When <span class=\"tex-span\"><i>D</i></span> is a subsequence of <span class=\"tex-span\"><i>A</i></span>, it is impossible to satisfy both conditions 1 and 4. Similarly, <span class=\"tex-span\"><i>B</i></span> must not be a subsequence of <span class=\"tex-span\"><i>C</i></span>. Are these sufficient conditions? Let's try to prove this hypothesis.</p><p>To simplify the description we will introduce some new variables. Let <span class=\"tex-span\"><i>A</i>'</span>, <span class=\"tex-span\"><i>B</i>'</span>, <span class=\"tex-span\"><i>C</i>'</span>, and <span class=\"tex-span\"><i>D</i>'</span> be strings that can be obtained by removing the first characters of <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span>, <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>D</i></span>. Let <span class=\"tex-span\"><i>c</i>1</span> and <span class=\"tex-span\"><i>c</i>2</span> be the first characters of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span>.</p><p><img alt=\" \" src=\"https://assets.codeforces.com/images/162/CF162D2.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Suppose that currently the conditions are satisfied (i.e. <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> is not a subsequence of <span class=\"tex-span\"><i>C</i></span>).</p> <ul> <li>If <span class=\"tex-span\"><i>c</i>1 = <i>c</i>2</span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>1 = <i>c</i>2</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>', <i>B</i>', <i>C</i>', <i>D</i>')</span> and this also satisies the conditions.</li> <li>If <span class=\"tex-span\"><i>c</i>1 ≠ <i>c</i>2</span> and <span class=\"tex-span\"><i>B</i>'</span> is not a subsequnce of <span class=\"tex-span\"><i>C</i></span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>1</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>', <i>B</i>', <i>C</i>, <i>D</i>)</span> and this also satisies the conditions.</li> <li>If <span class=\"tex-span\"><i>c</i>1 ≠ <i>c</i>2</span> and <span class=\"tex-span\"><i>D</i>'</span> is not a subsequnce of <span class=\"tex-span\"><i>A</i></span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>2</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>, <i>B</i>, <i>C</i>', <i>D</i>')</span> and this also satisies the conditions.</li> </ul><p>What happens if all of the above three conditions don't hold? In this case <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span> have the same length and <span class=\"tex-span\"><i>A</i> = <i>c</i>1<i>c</i>2<i>c</i>1<i>c</i>2...</span>, <span class=\"tex-span\"><i>B</i> = <i>c</i>2<i>c</i>1<i>c</i>2<i>c</i>1</span>. In particular the last two characters of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are swapped: there are different characters <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span>, <span class=\"tex-span\"><i>B</i> = ...<i>yx</i></span>. Now you found a new necessary condition! Generally, if <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are of the form <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span> and <span class=\"tex-span\"><i>B</i> = ...<i>yx</i></span>, the goal state is unreachable. If the last instruction is <span class=\"tex-span\"><i>x</i></span>, Vasya must be in the goal before the last instruction, but then Vasya will go further after the last instruction. If the last instruction is <span class=\"tex-span\"><i>y</i></span>, we will also get a contradiction.</p><p>Finally we have a solution. The goal state is reachable from the start state if and only if <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span> is not a subsequnce of <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span> are not of the form <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span>, <span class=\"tex-span\"><i>C</i> = ...<i>yx</i></span>. The remaining part is relatively easy, so I'll leave it as an exercise for readers. </p><h4><a href=\"//codeforces.com/problemset/problem/264/E\">Div1 E Roadside Trees</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/snuke\" title=\"Expert snuke\">snuke</a>)</h4><p>For this problem there are slides: Please check <a href=\"https://speakerdeck.com/snuke/codeforces162-div1-e\">here</a>.</p><p>UPD: Thank you for pointing out mistakes. They are fixed.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/265\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 162 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/264\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 162 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-293-6525\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"293\",\n blogEntryId: \"6478\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6525\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+54</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6525\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/rng_58\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/rng_58\">\n rng_58\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/21/2013 18:21\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6478#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6478#comments\">\n 67\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6535\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (52)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119220\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zuev93\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34580/avatar/db7a610a3504172f.jpg'/> </a>\n <div><a href=\"/profile/zuev93\" title=\"Specialist zuev93\" class=\"rated-user user-cyan\">zuev93</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119220\" href=\"?#comment-119220\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119220\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119220\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"34580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119220\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's nice to know that you idea for hard problem (Div 1 C) (for me certainly) is absolutely right=) But not enough time for debugging and AC=(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119220 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119220 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119220\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119221\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:02\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119221\" href=\"?#comment-119221\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119221\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119221\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have solved the div1 A problem using the mentioned algorithm, but I still receive that TLE error on the 31st test. I use Ruby. Is there a Ruby solution, which will pass the time test?</p><p>Here is my algorithm:</p> <pre><code>q = gets.chomp\nleft = []\nright = []\ni = 0\nq.each_char do |char|\n i += 1\n ((char == 'l') ? right : left) << i\nend\nputs left\nputs right.reverse\n</code></pre><p>Thanks in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119221 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119221 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119221\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119225\" commentParentId=\"119221\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119225\" href=\"?#comment-119225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119221\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ruby is slow. Use C++, FPC, Java, C# and it will be accepted.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119225\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119752\" commentParentId=\"119225\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Alireza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1843/avatar/6e649a6dce114e29.jpg'/> </a>\n <div><a href=\"/profile/Alireza\" title=\"Expert Alireza\" class=\"rated-user user-blue\">Alireza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 20:25\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119752\" href=\"?#comment-119752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119225\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1843\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My C++ Solution got also TLE. I used vectors and Microsoft Visual C++ Compiler! But using Gnu C++, It got Accepted!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119338\" commentParentId=\"119221\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/safeasmilk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4507/avatar/16117820f2dabe57.jpg'/> </a>\n <div><a href=\"/profile/safeasmilk\" title=\"Expert safeasmilk\" class=\"rated-user user-blue\">safeasmilk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 00:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119338\" href=\"?#comment-119338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119221\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"4507\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A citation from <a href=\"//codeforces.com/blog/entry/79\">here</a>:</p> <blockquote><p>It is not guaranteed that all the problems will have solutions in all the given languages (it's especially about the scripting ones).</p> </blockquote><p>Some folks managed to pass with Python, but it may happen that in Ruby I/O functions are much too slow to get AC.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119338\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119343\" commentParentId=\"119338\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 00:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119343\" href=\"?#comment-119343\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119338\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119343\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119343\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Tommorow there will be a match, and now I'm deciding which language to use. I have looked through all the submissions to that tasks, way most of them are written with C++, some Java, and even two Python solutions. Nothing else. My "second favourite" language is C#, and I have written a solution to the same problem in C#, but... <code>Превышено ограничение времени на тесте 35</code> (TLE on 35th). So, C# is too slow too? Here is my C# code</p> <pre><code>using System;\nusing System.Collections.Generic;\nusing System.Linq;\nusing System.Text;\n\nnamespace ConsoleApplication\n{\n class Program\n {\n public static void Main(string[] args)\n {\n var s = Console.ReadLine();\n var l = new List<int>();\n var r = new List<int>();\n var i = 0;\n foreach (char c in s)\n {\n i++;\n if(c=='l')\n {\n r.Add(i);\n }\n else\n {\n l.Add(i);\n }\n }\n foreach (int i12 in l)\n {\n Console.WriteLine(i12);\n }\n r.Reverse();\n foreach (int i2 in r)\n {\n Console.WriteLine(i2);\n }\n }\n }\n}\n\n</code></pre><p>In one of Java solutions I've seen class "FastScanner" with only method "FastRead", which reads from STDIO. If you think that the time issue is in IO, maybe there is a possibility to write some wrappers aroung Ruby's gets and puts? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119343 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119343 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119343\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119360\" commentParentId=\"119343\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119360\" href=\"?#comment-119360\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119343\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119360\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119360\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't now C# well but I think <code>WriteLine</code> method flushes the output. I inserted a hack into your solution and it passed: <a href=\"/contest/264/submission/2981286\" title=\"Submission 2981286 by dalex\">2981286</a></p><p>But it's better to write your own input/output class. I know user <a class=\"rated-user user-orange\" href=\"/profile/it4.kp\" title=\"Master it4.kp\">it4.kp</a> uses C# — look over his submissions.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119360 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119360 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119360\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119368\" commentParentId=\"119360\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119368\" href=\"?#comment-119368\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119360\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119368\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119368\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow, your advice is EXTREMELY useful! Thank you.</p><p>I have tried same in Ruby, and now it fails on 45th, not 31st test. I just replaced that <code>puts left</code> with puts <code>left.join("\\n")</code>, and the perfomance went up dramaticly. So, it seems that the weakest part in Ruby is the IO. Will think about it more.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119368 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119368 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119368\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119370\" commentParentId=\"119343\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:35\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119370\" href=\"?#comment-119370\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119343\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119370\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119370\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119370\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello. Just use StringBuilder. But don't forget that it uses a lot of memory. Example:<a href=\"https://codeforces.com/contest/265/submission/2974651\">http://codeforces.com/contest/265/submission/2974651</a> Also you can use a small buffer: <a href=\"https://codeforces.com/contest/265/submission/2974575\">http://codeforces.com/contest/265/submission/2974575</a> That is <a class=\"rated-user user-orange\" href=\"/profile/eduardische\" title=\"Master eduardische\">eduardische</a>'s advice. And.. Console.Write() works faster than Console.WriteLine(). <a href=\"https://codeforces.com/contest/265/submission/2973339\">http://codeforces.com/contest/265/submission/2973339</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119370 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119370 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119370\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:43\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119371\" href=\"?#comment-119371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can't view images from the problem Div1 D: 403 forbitten. :-(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119374\" commentParentId=\"119371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rng_58\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/733/avatar/12337379adfa9a4c.jpg'/> </a>\n <div><a href=\"/profile/rng_58\" title=\"Legendary Grandmaster rng_58\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">r</span>ng_58</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119374\" href=\"?#comment-119374\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119374\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119374\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fixed now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119374 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119374 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119374\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121846\" commentParentId=\"119374\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/11/2013 15:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121846\" href=\"?#comment-121846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119374\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems in problem D should be "A = c1c2c1c2..., C = c2c1c2c1." instead of "A = c1c2c1c2..., B = c2c1c2c1." And further should be C instead of B.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121846\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119379\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jill-jenn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/61244/avatar/379a15a12e1d32c7.jpg'/> </a>\n <div><a href=\"/profile/jill-jenn\" title=\"Expert jill-jenn\" class=\"rated-user user-blue\">jill-jenn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 02:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119379\" href=\"?#comment-119379\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119379\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119379\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"61244\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119379\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I assume you meant “when <em>i</em> is a <em>divisor</em> of <em>x</em>” instead of “when <em>i</em> is a <em>multiple</em> of <em>x</em>.”, in Good Sequences.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119379 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119379 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119379\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119385\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hupmscy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/26636/avatar/20574dd78ad48c95.jpg'/> </a>\n <div><a href=\"/profile/hupmscy\" title=\"Specialist hupmscy\" class=\"rated-user user-cyan\">hupmscy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:03\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119385\" href=\"?#comment-119385\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119385\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"26636\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119385\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div2 D Good Sequences, I don't understand why the sum of the number of the diviser from 1 to n is O(nlogn). Can someone prove it? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119385 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119385 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119385\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119391\" commentParentId=\"119385\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nishant4\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/nishant4\" title=\"Candidate Master nishant4\" class=\"rated-user user-violet\">nishant4</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:24\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119391\" href=\"?#comment-119391\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119385\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119391\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"57571\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119391\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let p be a number in the range 1 — n Now, p will divide n/p no.s Sum of no. of divisors — {Summation(p = 1 to n)} n/p <= n * {Summation(p = 1 to n)} 1/p = n * H(n) ( H is sum of harmonic series ) and since ln(n) < H(n) < ln(n) + 1 thus, n * ln(n) < Answer < n * (ln(n) + 1)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119391 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119391 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119391\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119388\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Martuza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12501/avatar/b25fe2e78d5c1ec.jpg'/> </a>\n <div><a href=\"/profile/Martuza\" title=\"Pupil Martuza\" class=\"rated-user user-green\">Martuza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:23\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119388\" href=\"?#comment-119388\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119388\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119388\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"12501\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119388\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 A / Div2 C Escape from Stones (Author: DEGwer) :</p><p>My solution is in O(2n), But code is so simple like it,</p> <pre><code>int main(){\n\tstring a;\n\tcin>>a;\n\tfor(long i=0; i<a.size(); i++)\n\tif(a[i]=='r') cout<<i+1<<endl;\n\t\t\n\tfor(long i=a.size()-1; i>=0; i--)\n\tif(a[i]=='l') cout<<i+1<<endl;\n\t\n return 0;\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119388 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119388 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119388\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"136294\" commentParentId=\"119388\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/moji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/80646/avatar/7b6fe780caa2c87c.jpg'/> </a>\n <div><a href=\"/profile/moji\" title=\"Candidate Master moji\" class=\"rated-user user-violet\">moji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2013 10:35\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-136294\" href=\"?#comment-136294\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119388\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"136294\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"136294\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"80646\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-136294\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>nice! But actually O(2n) = O(n) by the definition.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-136294 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-136294 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-136294\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120163\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Calvinxiao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Calvinxiao\" title=\"Expert Calvinxiao\" class=\"rated-user user-blue\">Calvinxiao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 09:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120163\" href=\"?#comment-120163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"54647\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 A/Div2 C</p><p><code>Finally, you should print the integers in the first vector by default order, after that, you should print the integers in the second vector in the reverse order.</code></p><p>should be: Finally, you should print the integers in the <strong>second</strong> vector by default order, after that, you should print the integers in the <strong>first</strong> vector in the reverse order.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120163\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Prestige\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19197/avatar/cf8ba2c2433b97.jpg'/> </a>\n <div><a href=\"/profile/Prestige\" title=\"Pupil Prestige\" class=\"rated-user user-green\">Prestige</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 14:30\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120170\" href=\"?#comment-120170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120170\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-11\"\r\n data-commentUserId=\"19197\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>2 problems of 7 are made by round author)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"214721\" commentParentId=\"120170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/catlak_profesor_mfb\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128467/avatar/81a7af0e3b8fb3f0.jpg'/> </a>\n <div><a href=\"/profile/catlak_profesor_mfb\" title=\"Candidate Master catlak_profesor_mfb\" class=\"rated-user user-violet\">catlak_profesor_mfb</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/25/2015 01:23\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-214721\" href=\"?#comment-214721\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"214721\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"128467\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-214721\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So what?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-214721 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-214721 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-214721\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"244903\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/OmaeWaMouShenDeiru\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88303/avatar/2756cc1cc5d9a15c.jpg'/> </a>\n <div><a href=\"/profile/OmaeWaMouShenDeiru\" title=\"Pupil OmaeWaMouShenDeiru\" class=\"rated-user user-green\">OmaeWaMouShenDeiru</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/10/2015 12:31\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-244903\" href=\"?#comment-244903\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"244903\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"88303\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-244903\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved DIV 2 C by looking at the input and output, I never understood the problem statement !! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-244903 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-244903 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-244903\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"251734\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ananth94\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/211746/avatar/72fbf14db6a1bcdc.jpg'/> </a>\n <div><a href=\"/profile/ananth94\" title=\"Specialist ananth94\" class=\"rated-user user-cyan\">ananth94</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2015 21:38\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-251734\" href=\"?#comment-251734\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"251734\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"211746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-251734\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could someone explain DIV1-C in more detail? Thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-251734 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-251734 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-251734\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"286092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/divyank1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143482/avatar/3da31c0aab0a7196.jpg'/> </a>\n <div><a href=\"/profile/divyank1\" title=\"Specialist divyank1\" class=\"rated-user user-cyan\">divyank1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/26/2016 16:46\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-286092\" href=\"?#comment-286092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"286092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143482\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-286092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div2 C <em>Escape from Stones</em> can also be solved using <em>Doubly Linked Lists</em>.</p><p>Maintain a pointer <code>operatingPointer</code> which is initialized to the <code>head</code> of list (head of the list contains 1).</p><p>if we encounter 'l' at <code>ith</code> position of input add i+1 to the <code>left</code> of <code>operatingPointer</code> and update <code>operatingPointer</code> to newly created node.</p><p>Similarly if we encounter 'r' at <code>ith</code> position of the string add i+1 to the <code>right</code> of <code>operatingPointer</code> and update <code>operatingPointer</code> to newly created node.</p><p>Then print the whole list.</p><p><a href=\"//codeforces.com/contest/264/submission/16956916\">Implementation using Doubly Linked Lists</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-286092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-286092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-286092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"296233\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/szawinis\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/413991/avatar/77a65dc71d2f7f59.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/szawinis\" title=\"Candidate Master szawinis\" class=\"rated-user user-violet\">szawinis</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/28/2016 05:41\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-296233\" href=\"?#comment-296233\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"296233\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"413991\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-296233\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2 D/ Div 1 B, why do we have to update d[i] for all divisors of x? Can someone explain? Thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-296233 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-296233 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-296233\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"640442\" commentParentId=\"296233\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbhishekAg\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/AbhishekAg\" title=\"Expert AbhishekAg\" class=\"rated-user user-blue\">AbhishekAg</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2020 13:23\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-640442\" href=\"?#comment-640442\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-296233\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"640442\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"826040\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-640442\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Getting wrong answer for test 13 in div1 b......Can someone explain what is wrong in <a href=\"https://codeforces.com/problemset/submission/264/83518635\">this</a>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-640442 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-640442 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-640442\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"301587\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/HalfBloodPrince\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/332453/avatar/a1a516d280a7dbef.jpg'/> </a>\n <div><a href=\"/profile/HalfBloodPrince\" title=\"Expert HalfBloodPrince\" class=\"rated-user user-blue\">HalfBloodPrince</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/21/2016 18:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-301587\" href=\"?#comment-301587\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"301587\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"301587\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"332453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-301587\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could a top-down approach be used for div1 B/div2 D? I tried a top down approach but I am not able to memoize it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-301587 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-301587 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-301587\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310750\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/red_dust\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/417513/avatar/d7a2f654b2949853.jpg'/> </a>\n <div><a href=\"/profile/red_dust\" title=\"Expert red_dust\" class=\"rated-user user-blue\">red_dust</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/19/2016 11:02\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310750\" href=\"?#comment-310750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"417513\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div A/Div2 C Escape from Stones the algorithm is easy to understand if someone explains it,</p><p>but I don't understand how this solution came to be, which trail of thought led to this solution.</p><p>can someone please explain it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"331390\" commentParentId=\"310750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marlonbymendes\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/358576/avatar/a4da054df60816b9.jpg'/> </a>\n <div><a href=\"/profile/marlonbymendes\" title=\"Expert marlonbymendes\" class=\"rated-user user-blue\">marlonbymendes</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/18/2016 00:15\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-331390\" href=\"?#comment-331390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-310750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"331390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"358576\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-331390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Read my comment below.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-331390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-331390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-331390\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"331388\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marlonbymendes\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/358576/avatar/a4da054df60816b9.jpg'/> </a>\n <div><a href=\"/profile/marlonbymendes\" title=\"Expert marlonbymendes\" class=\"rated-user user-blue\">marlonbymendes</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/18/2016 00:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-331388\" href=\"?#comment-331388\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"331388\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"358576\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-331388\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think editorial nor comments explanation on solution <a href=\"/contest/264/problem/A\" title=\"Codeforces Round 162 (Div. 1)\">264A - Escape from Stones</a> are intuitive so I'll try to explain how I came up with a solution. </p><p>You can visualize the problem as a binary tree. Each node is responsable for a interval <strong>[a, b]</strong>. Starting from the root, responsable for <strong>[0, 1]</strong>, if you go left then root will have a left child responsable for interval <strong>[0, 1 / 2]</strong>. Since you're a left child, last time the stone fell on position 1 / 2, the end point of the interval.</p><p>Note that from that child, it doesn't matter if you go left or right: the stone will never fall on a position bigger than 1 / 2 (the end point). The ideia is: since a stone always fall on the midpoint <strong>(a + b) / 2</strong> of the lower and end points, it can never fall after the endpoint. In fact, the stone must fall infinitely many times to the right to reach that endpoint. So, we were on a node [0, 1], the stone fell and we jumped to the left, creating a left child [0, 1 / 2] and we now know that there is no way the stone will every fall to a position > 1 / 2. This means that in the final solution, the current node [0, 1 / 2] will come AFTER all nodes (descendents) that come after this one.</p><p>If we jumped to the right instead, creating a right child responsable for interval [1 / 2, 1] we can show the same way that the stone will never fall before the starting point 1 / 2. This means that the current node will com BEFORE all nodes (descendents) that come after this one, since we know that the stone can't fall on a postion < 1 / 2 from now on.</p><p>This is an algorithm: if in the i'th stone we jumped to the left, we now that stone i will become AFTER all next stones. If we jumped right, stone i will become BEFORE all next stones.</p><p>Code: <a href=\"/contest/264/submission/23071895\" title=\"Submission 23071895 by marlonbymendes\">23071895</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-331388 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-331388 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-331388\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"386173\" commentParentId=\"331388\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ameyanator\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/464121/avatar/e34f7dc2b59a7b4c.jpg'/> </a>\n <div><a href=\"/profile/ameyanator\" title=\"Specialist ameyanator\" class=\"rated-user user-cyan\">ameyanator</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/18/2017 10:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-386173\" href=\"?#comment-386173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-331388\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"386173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"464121\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-386173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Awesome explanation thanks! :')</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-386173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-386173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-386173\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360590\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/the_an0nym0us\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/303591/avatar/41fc9495b1ea2f27.jpg'/> </a>\n <div><a href=\"/profile/the_an0nym0us\" title=\"Specialist the_an0nym0us\" class=\"rated-user user-cyan\">the_an0nym0us</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/17/2017 08:56\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360590\" href=\"?#comment-360590\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360590\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"303591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360590\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Strange! My C++ code got accepted with printf but got TLE with cout. This is too harsh</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360590 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360590 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360590\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360690\" commentParentId=\"360590\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/559880/avatar/fd0565aa541e0d1.jpg'/> </a>\n <div><a href=\"/profile/Guy\" title=\"Candidate Master Guy\" class=\"rated-user user-violet\">Guy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/18/2017 10:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360690\" href=\"?#comment-360690\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-360590\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"360690\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"360690\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"559880\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360690\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>printf is faster than cout. if u want to use cout its better type ios::sync_with_stdio(false),cin.tie(0),cout.tie(0); in your code this make cout fast</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360690 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360690 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360690\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"365999\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akhi29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207626/avatar/c39a3ca998f53094.jpg'/> </a>\n <div><a href=\"/profile/akhi29\" title=\"Pupil akhi29\" class=\"rated-user user-green\">akhi29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2017 01:33\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-365999\" href=\"?#comment-365999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"365999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"365999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207626\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-365999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm unable to solve Escape from Stones in java. In spite of using fast io, it always gives me a TLE now matter how much i optimize it <a href=\"//codeforces.com/contest/264/submission/27712057\">sol</a> did anyone get it AC in java?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-365999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-365999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-365999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"385333\" commentParentId=\"365999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zodiacleo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/zodiacleo\" title=\"Pupil zodiacleo\" class=\"rated-user user-green\">zodiacleo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2017 11:29\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-385333\" href=\"?#comment-385333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-365999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"385333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"145879\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-385333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi <a class=\"rated-user user-green\" href=\"/profile/akhi29\" title=\"Pupil akhi29\">akhi29</a><br />Two points-<br />1. Try to use <code>StringBuilder</code> (popular practice among Java user's) instead of directly printing to the output console.<br />2. When you call, <code>close()</code> of <code>PrintStream</code>, it isn't obliged to flush your output to the console. You need to call <code>flush()</code> explicitly to ensure that the data, if present in the buffer is flushed to the output console. You can refer the modified submission <a href=\"/contest/264/submission/30322735\" title=\"Submission 30322735 by zodiacleo\">30322735</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-385333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-385333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-385333\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587566\" commentParentId=\"385333\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akhi29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207626/avatar/c39a3ca998f53094.jpg'/> </a>\n <div><a href=\"/profile/akhi29\" title=\"Pupil akhi29\" class=\"rated-user user-green\">akhi29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 01:45\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587566\" href=\"?#comment-587566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-385333\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207626\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks zodiacleo</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"379370\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Target2018\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/295556/avatar/f6fe0b640b7fee7.jpg'/> </a>\n <div><a href=\"/profile/Target2018\" title=\"Newbie Target2018\" class=\"rated-user user-gray\">Target2018</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/18/2017 18:55\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-379370\" href=\"?#comment-379370\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"379370\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"295556\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-379370\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In <a href=\"//codeforces.com/contest/265/problem/C\">DIV 2 C</a> I took 2 variables hi = 1 and lo = 0, if character is 'l' then I just change hi = (hi + lo) / 2 otherwise lo = (hi + lo) / 2 and mapped the value, sort them and print them, but got WA on Testcase 11, could you please tell me what is I'm missing?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-379370 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-379370 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-379370\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"384618\" commentParentId=\"379370\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bibhuti\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/561745/avatar/eb1f97e82517cf9e.jpg'/> </a>\n <div><a href=\"/profile/Bibhuti\" title=\"Specialist Bibhuti\" class=\"rated-user user-cyan\">Bibhuti</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/07/2017 19:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-384618\" href=\"?#comment-384618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-379370\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"384618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"561745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-384618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I hope it may be because of the precision problem. I am also facing the same and below is my solution</p><p><a href=\"/contest/264/submission/30185936\" title=\"Submission 30185936 by Bibhuti\">30185936</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-384618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-384618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-384618\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"396488\" commentParentId=\"384618\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/neroond\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/375945/avatar/2a26526cf4420757.jpg'/> </a>\n <div><a href=\"/profile/neroond\" title=\"Expert neroond\" class=\"rated-user user-blue\">neroond</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/21/2017 13:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-396488\" href=\"?#comment-396488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-384618\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"396488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"375945\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-396488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in DIV2 D what will be answer in case 5 : 2 4 8 6 9. My solution that got AC. outputs 5, but how? 8 is bigger than 6 they can't form a sequence </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-396488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-396488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-396488\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"411637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sabertooth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/547698/avatar/2106fe4acab8cfe4.jpg'/> </a>\n <div><a href=\"/profile/sabertooth\" title=\"Specialist sabertooth\" class=\"rated-user user-cyan\">sabertooth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2018 07:14\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-411637\" href=\"?#comment-411637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"411637\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"411637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"547698\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-411637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In <strong>Div 1 A</strong> Stones falls in 'k' position and print the stone position from left</p><p>I calculated 'k' and 'd' as k=(X+Y)/2 and d=(Y-X)/2 And if 'l' then x-=d otherwise y+=d. then sorted the array which contains 'k' s value and its position no. but my implementation isn't matching with the test case..</p><p>Did I misunderstood the ques or my idea is wrong?</p><p><a href=\"https://paste.ubuntu.com/26503881/\">CODE</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-411637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-411637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-411637\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"453240\" commentParentId=\"411637\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wallcrawler\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/446649/avatar/28b029f94566d9b0.jpg'/> </a>\n <div><a href=\"/profile/wallcrawler\" title=\"Expert wallcrawler\" class=\"rated-user user-blue\">wallcrawler</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/22/2018 10:35\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-453240\" href=\"?#comment-453240\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-411637\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"453240\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"446649\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-453240\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The thing is that, suppose you only go left then it means that the stones would be at 1/2,1/4,1/8,...till 1/(2^(10^6)) (considering maximum length of the string) which can't be stored in the float value.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-453240 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-453240 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-453240\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469926\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/umangahuja1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/480801/avatar/6a0f8d27102d0ec0.jpg'/> </a>\n <div><a href=\"/profile/umangahuja1\" title=\"Expert umangahuja1\" class=\"rated-user user-blue\">umangahuja1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 11:09\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469926\" href=\"?#comment-469926\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"469926\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"480801\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469926\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For those facing TLE in the problem Div1 A (Div2 C Escape from Stones) in C++ even with <code>O(N)</code> time complexity the reason can be <code>endl vs '\\n'</code>.</p><p><code>'\\n</code>' inserts a new line to the output stream while</p><p><code>endl</code> inserts a new line as well as flushes the output stream.</p><p>So using <code>'\\n'</code>can solve the TLE issue.</p><p>Also you can use fast IO with cin/cout too instead of using scanf/printf by adding these lines in your code.</p><p><code>ios::sync_with_stdio(false);</code></p><p><code>cin.tie(0);</code></p><p><code>cout.tie(0);</code></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469926 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469926 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469926\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"494267\" commentParentId=\"469926\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SohrabRoohi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SohrabRoohi\" title=\"Specialist SohrabRoohi\" class=\"rated-user user-cyan\">SohrabRoohi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/22/2019 01:54\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-494267\" href=\"?#comment-494267\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-469926\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"494267\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"620634\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-494267\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Believe it or not this actually solved the problem for me. I was using a linked list and basically pushing to the front and back and was confused how I was getting TLE with 1,000,000 O(1) operations. I ended up writing my own code for a linked list and still failed case 31, changing the endl to \\n made it accepted. This made it go from 2000 ms TLE to 233 ms, thank you for your post.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-494267 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-494267 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-494267\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512701\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pseudocoder10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/pseudocoder10\" title=\"Master pseudocoder10\" class=\"rated-user user-orange\">pseudocoder10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2019 15:13\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512701\" href=\"?#comment-512701\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"512701\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"512701\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"786409\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512701\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved div1A using a binary tree, if character is l then i add to the left of parent node otherwise i add to the right, then an inorder traversal will give the answer but im getting TLE at testcase 31 idk why since my code is implemented in O(n) complexity. My solution(<a href=\"https://codeforces.com/contest/264/submission/54413614\">https://codeforces.com/contest/264/submission/54413614</a>)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512701 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512701 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512701\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"553043\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wolfie.\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/889894/avatar/b1389c1ceb58933b.jpg'/> </a>\n <div><a href=\"/profile/wolfie.\" title=\"Expert wolfie.\" class=\"rated-user user-blue\">wolfie.</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2019 17:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-553043\" href=\"?#comment-553043\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"553043\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"553043\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"889894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-553043\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Something is wrong with the testing of the question Div 1(A)/ Div2(C) . Got 2 TLE's on a O(n) solution [Test Case 31] , changed endl and to '\\n' and then got runtime error on test 41. </p><p>TLE — <a href=\"https://codeforces.com/contest/265/submission/63245660\">https://codeforces.com/contest/265/submission/63245660</a> Runtime Error — <a href=\"https://codeforces.com/contest/265/submission/63246396\">https://codeforces.com/contest/265/submission/63246396</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-553043 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-553043 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-553043\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621308\" commentParentId=\"553043\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/UNOwen98\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/UNOwen98\" title=\"Expert UNOwen98\" class=\"rated-user user-blue\">UNOwen98</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 09:56\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621308\" href=\"?#comment-621308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-553043\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1254135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am facing the same problem. Were you able to fix it ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621308\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621403\" commentParentId=\"621308\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wolfie.\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/889894/avatar/b1389c1ceb58933b.jpg'/> </a>\n <div><a href=\"/profile/wolfie.\" title=\"Expert wolfie.\" class=\"rated-user user-blue\">wolfie.</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621403\" href=\"?#comment-621403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-621308\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"889894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, i kept on getting runtime error with that approach.. so i changed my implementation a little bit, and it got accepted. <a href=\"https://codeforces.com/contest/265/submission/63246871\">Accepted Solution.</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621435\" commentParentId=\"621403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/UNOwen98\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/UNOwen98\" title=\"Expert UNOwen98\" class=\"rated-user user-blue\">UNOwen98</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 13:39\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621435\" href=\"?#comment-621435\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-621403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621435\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"1254135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621435\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I had to do this too. I guess the problem was caused because the second loop ( which is being run backwards ) was trying to access some invalid memory. The problems gets fixed when the array is reversed and loop is run forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621435 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621435 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621435\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"664098\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iabhishek15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1226114/avatar/6ce33a9f7d454deb.jpg'/> </a>\n <div><a href=\"/profile/iabhishek15\" title=\"Expert iabhishek15\" class=\"rated-user user-blue\">iabhishek15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2020 19:31\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-664098\" href=\"?#comment-664098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"664098\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"664098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1226114\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-664098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an another approach for div1B. for each number check the maxm times a divisor has occurred from all the divisors of a number and then increase the maxm by 1 and iterate again and update all the divisors</p><p>code <a href=\"/contest/264/submission/87253298\" title=\"Submission 87253298 by iabhishek15\">87253298</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-664098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-664098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-664098\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1035696\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ahmed_ElGendy56\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2725312/avatar/e34f70ed817bafea.jpg'/> </a>\n <div><a href=\"/profile/Ahmed_ElGendy56\" title=\"Pupil Ahmed_ElGendy56\" class=\"rated-user user-green\">Ahmed_ElGendy56</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/07/2023 19:42\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1035696\" href=\"?#comment-1035696\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1035696\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-7\"\r\n data-commentUserId=\"2725312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1035696\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you are using C++ for solving (Div1 A / Div2 C Escape from Stones) and got a TLE error on the 31st test you have to be sure you are using ("\\n") instead of (endl) because (endl) takes more time for flushing.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1035696 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1035696 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1035696\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046784\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/oishi_161\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2006012/avatar/8428423d6c055dae.jpg'/> </a>\n <div><a href=\"/profile/oishi_161\" title=\"Newbie oishi_161\" class=\"rated-user user-gray\">oishi_161</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 11:18\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046784\" href=\"?#comment-1046784\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046784\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2006012\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046784\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem div2 B in more detail?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046784 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1046784 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1046784\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046792\" commentParentId=\"1046784\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SummerSky\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/419016/avatar/8ddf3c5c2dc6bf44.jpg'/> </a>\n <div><a href=\"/profile/SummerSky\" title=\"Expert SummerSky\" class=\"rated-user user-blue\">SummerSky</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 11:36\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046792\" href=\"?#comment-1046792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-1046784\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"419016\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Note that we can only move to the next tree, but not to the previous one. So, to eat all the nuts, we must start from the first tree and visit one by one until we reach the final one. When we are on the top of some tree-i (because we must go to the top to eat that nut), and eat the nut, then we should move to the next tree. If next tree has lower height, we have to move down to the same height and then jump (to save time). Otherwise, we can directly jump to the next tree (also to save time). </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1046792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1046792\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046818\" commentParentId=\"1046792\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/oishi_161\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2006012/avatar/8428423d6c055dae.jpg'/> </a>\n <div><a href=\"/profile/oishi_161\" title=\"Newbie oishi_161\" class=\"rated-user user-gray\">oishi_161</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 12:46\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046818\" href=\"?#comment-1046818\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-1046792\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046818\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2006012\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046818\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for your help.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046818 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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Good Sequences"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Good Sequences</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Squirrel Liss is interested in sequences. She also has preferences of integers. She thinks <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> are <span class=\"tex-font-style-it\">good</span>.</p><p>Now she is interested in good sequences. A sequence <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>k</i></sub></span> is called <span class=\"tex-font-style-it\">good</span> if it satisfies the following three conditions:</p><ul> <li> The sequence is strictly increasing, i.e. <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> < <i>x</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span> for each <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>k</i> - 1)</span>. </li><li> No two adjacent elements are coprime, i.e. <span class=\"tex-span\"><i>gcd</i>(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>x</i><sub class=\"lower-index\"><i>i</i> + 1</sub>) > 1</span> for each <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>k</i> - 1)</span> (where <span class=\"tex-span\"><i>gcd</i>(<i>p</i>, <i>q</i>)</span> denotes the greatest common divisor of the integers <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>q</i></span>). </li><li> All elements of the sequence are good integers. </li></ul><p>Find the length of the longest good sequence.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input consists of two lines. The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>) — the number of good integers. The second line contains a single-space separated list of good integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> in strictly increasing order (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">5</sup>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> < <i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the length of the longest good sequence.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>2 3 4 6 9<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9<br/>1 2 3 5 6 7 8 9 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, the following sequences are examples of good sequences: [2; 4; 6; 9], [2; 4; 6], [3; 9], [6]. The length of the longest good sequence is 4.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"8f31da8e45639247d21fd2145000abbb\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"19843d15aee6a49b49ab812b3433503e5e4f1193\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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data-uuid=\"ps_6354da0f13a9707c40be072538e0bdac0d4208a9\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Good Sequences</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Squirrel Liss is interested in sequences. She also has preferences of integers. She thinks <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> are <span class=\"tex-font-style-it\">good</span>.</p><p>Now she is interested in good sequences. A sequence <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>, <i>x</i><sub class=\"lower-index\">2</sub>, ..., <i>x</i><sub class=\"lower-index\"><i>k</i></sub></span> is called <span class=\"tex-font-style-it\">good</span> if it satisfies the following three conditions:</p><ul> <li> The sequence is strictly increasing, i.e. <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub> < <i>x</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span> for each <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>k</i> - 1)</span>. </li><li> No two adjacent elements are coprime, i.e. <span class=\"tex-span\"><i>gcd</i>(<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>x</i><sub class=\"lower-index\"><i>i</i> + 1</sub>) > 1</span> for each <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>k</i> - 1)</span> (where <span class=\"tex-span\"><i>gcd</i>(<i>p</i>, <i>q</i>)</span> denotes the greatest common divisor of the integers <span class=\"tex-span\"><i>p</i></span> and <span class=\"tex-span\"><i>q</i></span>). </li><li> All elements of the sequence are good integers. </li></ul><p>Find the length of the longest good sequence.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input consists of two lines. The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>) — the number of good integers. The second line contains a single-space separated list of good integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> in strictly increasing order (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">5</sup>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> < <i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the length of the longest good sequence.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />2 3 4 6 9<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>9<br />1 2 3 5 6 7 8 9 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, the following sequences are examples of good sequences: [2; 4; 6; 9], [2; 4; 6], [3; 9], [6]. 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:45</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4298c77d77d8d2562e182e69f443373f'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final 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style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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user-legendary\"><span class=\"legendary-user-first-letter\">r</span>ng_58</a>,\r\n <span class=\"format-humantime\" title=\"Jan/21/2013 18:21\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"//codeforces.com/problemset/problem/265/A\">Div2 A Colorful Stones (Simplified Edition)</a> (Author: <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>)</h4><p>In this problem you just need to implement what is written in the statement. Make a variable that holds the position of Liss, and simulate the instructions one by one.</p><h4><a href=\"//codeforces.com/problemset/problem/265/B\">Div2 B Roadside Trees (Simplified Edition)</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/snuke\" title=\"Expert snuke\">snuke</a>)</h4><p>The optimal path of Liss is as follows: First she starts from the root of tree 1. Walk up the tree to the top and eat a nut. Walk down to the height <span class=\"tex-span\"><i>min</i>(<i>h</i><sub class=\"lower-index\">1</sub>, <i>h</i><sub class=\"lower-index\">2</sub>)</span>. Jump to the tree 2. Walk up the tree to the top and eat a nut. Walk down to the height <span class=\"tex-span\"><i>min</i>(<i>h</i><sub class=\"lower-index\">2</sub>, <i>h</i><sub class=\"lower-index\">3</sub>)</span>, <span class=\"tex-span\">...</span> and so on.</p><h4><a href=\"//codeforces.com/problemset/problem/264/A\">Div1 A / Div2 C Escape from Stones</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/DEGwer\" title=\"Expert DEGwer\">DEGwer</a>)</h4><p>In this problem, there are many simple algorithms which works in <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. One of them (which I intended) is following:</p><p>You should prepare 2 vectors. If <span class=\"tex-span\"><i>s</i>[<i>i</i>] = '<i>l</i>'</span>, you should push i to the first vector, and if <span class=\"tex-span\"><i>s</i>[<i>i</i>] = '<i>r</i>'</span>, you should push i to the second vector. Finally, you should print the integers in the second vector by default order, after that, you should print the integers in the first vector in the reverse order.</p><p>This algorithm works because if Liss divides an interval into two intervals <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> and she enters <span class=\"tex-span\"><i>A</i></span>, she will never enter <span class=\"tex-span\"><i>B</i></span>.</p><h4><a href=\"//codeforces.com/problemset/problem/264/B\">Div1 B / Div2 D Good Sequences</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/DEGwer\" title=\"Expert DEGwer\">DEGwer</a>)</h4><p>The main idea is DP. Let's define <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> as the maximal value of the length of the good sequence whose last element is <span class=\"tex-span\"><i>x</i></span>, and define <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> as the (maximal value of <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> where <span class=\"tex-span\"><i>x</i></span> is divisible by <span class=\"tex-span\"><i>i</i></span>).</p><p>You should calculate <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> in the increasing order of x. The value of <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> is (maximal value of <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> where <span class=\"tex-span\"><i>i</i></span> is a divisor of <span class=\"tex-span\"><i>x</i></span>) + 1. After you calculate <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span>, for each divisor <span class=\"tex-span\"><i>i</i></span> of <span class=\"tex-span\"><i>x</i></span>, you should update <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> too.</p><p>This algorithm works in <span class=\"tex-span\"><i>O</i>(<i>nlogn</i>)</span> because the sum of the number of the divisor from 1 to <span class=\"tex-span\"><i>n</i></span> is <span class=\"tex-span\"><i>O</i>(<i>nlogn</i>)</span>.</p><p>Note that there is a corner case. When the set is <span class=\"tex-span\">{1}</span>, you should output 1.</p><h4><a href=\"//codeforces.com/problemset/problem/264/C\">Div1 C / Div2 E Choosing Balls</a> (Author: <a class=\"rated-user user-orange\" href=\"/profile/hogloid\" title=\"Master hogloid\">hogloid</a>)</h4><p>There are many <span class=\"tex-span\"><i>O</i>(<i>Q</i> * <i>N</i> * <i>logN</i>)</span> solutions using segment trees or other data structures, but probably they will get time limit exceeded.</p><p>We can solve each query independently. First, let's consider the following DP algorithm.</p><p><span class=\"tex-span\"><i>dp</i>[<i>c</i>]</span> := the maximal value of a sequence whose last ball's color is <span class=\"tex-span\"><i>c</i></span></p><p>For each ball <span class=\"tex-span\"><i>i</i></span>, we want to update the array. Let the <span class=\"tex-span\"><i>i</i></span>-th ball's color be <span class=\"tex-span\"><i>col</i>[<i>i</i>]</span>, the <span class=\"tex-span\"><i>i</i></span>-th ball's value be <span class=\"tex-span\"><i>val</i>[<i>i</i>]</span>, and the maximal value of dp array other than <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> be <span class=\"tex-span\"><i>otherMAX</i></span>. We can update the value of <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> to <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]] + <i>val</i>[<i>i</i>] × <i>a</i></span> or <span class=\"tex-span\"><i>otherMAX</i> + <i>val</i>[<i>i</i>] × <i>b</i></span>. Here, we only need to know <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> and <span class=\"tex-span\"><i>otherMAX</i></span>. If we remember the biggest two values of <span class=\"tex-span\"><i>dp</i></span> array in that time and their indexes in the array, <span class=\"tex-span\"><i>otherMAX</i></span> can be calculated using the biggest two values, which always include maximal values of dp array other than any particular color.</p><p>Since the values of dp array don't decrease, we can update the biggest two values in <span class=\"tex-span\"><i>O</i>(1)</span>. Finally, the answer for the query is the maximal value of <span class=\"tex-span\"><i>dp</i></span> array.</p><p>The complexity of the described algorithm is <span class=\"tex-span\"><i>O</i>(<i>QN</i>)</span>.</p><h4><a href=\"//codeforces.com/problemset/problem/264/D\">Div1 D Colorful Stones</a> (Author: <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>)</h4><p>First, let's consider a simpler version of the problem: You are given a start state and a goal state. Check whether the goal state is reachable from the start state.</p><p>Define <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span>, <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>D</i></span> as in the picture below, and let <span class=\"tex-span\"><i>I</i></span> be the string of your instructions. <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are substrings of <span class=\"tex-span\"><i>s</i></span>, and <span class=\"tex-span\"><i>C</i></span> and <span class=\"tex-span\"><i>D</i></span> are substrings of <span class=\"tex-span\"><i>t</i></span>.</p><p><img alt=\" \" src=\"https://assets.codeforces.com/images/162/CF162D1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>It is possible to reach the goal state from the start state if there exists an instruction <span class=\"tex-span\"><i>I</i></span> such that:</p> <ul> <li>1 <span class=\"tex-span\"><i>A</i></span> is a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>2 <span class=\"tex-span\"><i>B</i></span> is not a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>3 <span class=\"tex-span\"><i>C</i></span> is a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>4 <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> </ul><p>So we want to check if such string <span class=\"tex-span\"><i>I</i></span> exists. (string <span class=\"tex-span\"><i>s</i>1</span> is called a subsequence of <span class=\"tex-span\"><i>s</i>2</span> if it is possible to get <span class=\"tex-span\"><i>s</i>2</span> by removing some characters of <span class=\"tex-span\"><i>s</i>1</span>)</p><p>There are some obvious "NO" cases. When <span class=\"tex-span\"><i>D</i></span> is a subsequence of <span class=\"tex-span\"><i>A</i></span>, it is impossible to satisfy both conditions 1 and 4. Similarly, <span class=\"tex-span\"><i>B</i></span> must not be a subsequence of <span class=\"tex-span\"><i>C</i></span>. Are these sufficient conditions? Let's try to prove this hypothesis.</p><p>To simplify the description we will introduce some new variables. Let <span class=\"tex-span\"><i>A</i>'</span>, <span class=\"tex-span\"><i>B</i>'</span>, <span class=\"tex-span\"><i>C</i>'</span>, and <span class=\"tex-span\"><i>D</i>'</span> be strings that can be obtained by removing the first characters of <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span>, <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>D</i></span>. Let <span class=\"tex-span\"><i>c</i>1</span> and <span class=\"tex-span\"><i>c</i>2</span> be the first characters of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span>.</p><p><img alt=\" \" src=\"https://assets.codeforces.com/images/162/CF162D2.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Suppose that currently the conditions are satisfied (i.e. <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> is not a subsequence of <span class=\"tex-span\"><i>C</i></span>).</p> <ul> <li>If <span class=\"tex-span\"><i>c</i>1 = <i>c</i>2</span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>1 = <i>c</i>2</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>', <i>B</i>', <i>C</i>', <i>D</i>')</span> and this also satisies the conditions.</li> <li>If <span class=\"tex-span\"><i>c</i>1 ≠ <i>c</i>2</span> and <span class=\"tex-span\"><i>B</i>'</span> is not a subsequnce of <span class=\"tex-span\"><i>C</i></span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>1</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>', <i>B</i>', <i>C</i>, <i>D</i>)</span> and this also satisies the conditions.</li> <li>If <span class=\"tex-span\"><i>c</i>1 ≠ <i>c</i>2</span> and <span class=\"tex-span\"><i>D</i>'</span> is not a subsequnce of <span class=\"tex-span\"><i>A</i></span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>2</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>, <i>B</i>, <i>C</i>', <i>D</i>')</span> and this also satisies the conditions.</li> </ul><p>What happens if all of the above three conditions don't hold? In this case <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span> have the same length and <span class=\"tex-span\"><i>A</i> = <i>c</i>1<i>c</i>2<i>c</i>1<i>c</i>2...</span>, <span class=\"tex-span\"><i>B</i> = <i>c</i>2<i>c</i>1<i>c</i>2<i>c</i>1</span>. In particular the last two characters of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are swapped: there are different characters <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span>, <span class=\"tex-span\"><i>B</i> = ...<i>yx</i></span>. Now you found a new necessary condition! Generally, if <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are of the form <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span> and <span class=\"tex-span\"><i>B</i> = ...<i>yx</i></span>, the goal state is unreachable. If the last instruction is <span class=\"tex-span\"><i>x</i></span>, Vasya must be in the goal before the last instruction, but then Vasya will go further after the last instruction. If the last instruction is <span class=\"tex-span\"><i>y</i></span>, we will also get a contradiction.</p><p>Finally we have a solution. The goal state is reachable from the start state if and only if <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span> is not a subsequnce of <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span> are not of the form <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span>, <span class=\"tex-span\"><i>C</i> = ...<i>yx</i></span>. The remaining part is relatively easy, so I'll leave it as an exercise for readers. </p><h4><a href=\"//codeforces.com/problemset/problem/264/E\">Div1 E Roadside Trees</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/snuke\" title=\"Expert snuke\">snuke</a>)</h4><p>For this problem there are slides: Please check <a href=\"https://speakerdeck.com/snuke/codeforces162-div1-e\">here</a>.</p><p>UPD: Thank you for pointing out mistakes. They are fixed.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/265\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 162 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/264\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 162 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-293-6525\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"293\",\n blogEntryId: \"6478\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6525\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+54</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6525\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/rng_58\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/rng_58\">\n rng_58\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/21/2013 18:21\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6478#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6478#comments\">\n 67\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6535\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (52)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119220\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zuev93\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34580/avatar/db7a610a3504172f.jpg'/> </a>\n <div><a href=\"/profile/zuev93\" title=\"Specialist zuev93\" class=\"rated-user user-cyan\">zuev93</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119220\" href=\"?#comment-119220\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119220\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119220\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"34580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119220\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's nice to know that you idea for hard problem (Div 1 C) (for me certainly) is absolutely right=) But not enough time for debugging and AC=(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119220 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119220 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119220\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119221\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:02\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119221\" href=\"?#comment-119221\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119221\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119221\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have solved the div1 A problem using the mentioned algorithm, but I still receive that TLE error on the 31st test. I use Ruby. Is there a Ruby solution, which will pass the time test?</p><p>Here is my algorithm:</p> <pre><code>q = gets.chomp\nleft = []\nright = []\ni = 0\nq.each_char do |char|\n i += 1\n ((char == 'l') ? right : left) << i\nend\nputs left\nputs right.reverse\n</code></pre><p>Thanks in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119221 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119221 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119221\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119225\" commentParentId=\"119221\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119225\" href=\"?#comment-119225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119221\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ruby is slow. Use C++, FPC, Java, C# and it will be accepted.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119225\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119752\" commentParentId=\"119225\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Alireza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1843/avatar/6e649a6dce114e29.jpg'/> </a>\n <div><a href=\"/profile/Alireza\" title=\"Expert Alireza\" class=\"rated-user user-blue\">Alireza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 20:25\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119752\" href=\"?#comment-119752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119225\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1843\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My C++ Solution got also TLE. I used vectors and Microsoft Visual C++ Compiler! But using Gnu C++, It got Accepted!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119338\" commentParentId=\"119221\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/safeasmilk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4507/avatar/16117820f2dabe57.jpg'/> </a>\n <div><a href=\"/profile/safeasmilk\" title=\"Expert safeasmilk\" class=\"rated-user user-blue\">safeasmilk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 00:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119338\" href=\"?#comment-119338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119221\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"4507\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A citation from <a href=\"//codeforces.com/blog/entry/79\">here</a>:</p> <blockquote><p>It is not guaranteed that all the problems will have solutions in all the given languages (it's especially about the scripting ones).</p> </blockquote><p>Some folks managed to pass with Python, but it may happen that in Ruby I/O functions are much too slow to get AC.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119338\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119343\" commentParentId=\"119338\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 00:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119343\" href=\"?#comment-119343\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119338\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119343\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119343\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Tommorow there will be a match, and now I'm deciding which language to use. I have looked through all the submissions to that tasks, way most of them are written with C++, some Java, and even two Python solutions. Nothing else. My "second favourite" language is C#, and I have written a solution to the same problem in C#, but... <code>Превышено ограничение времени на тесте 35</code> (TLE on 35th). So, C# is too slow too? Here is my C# code</p> <pre><code>using System;\nusing System.Collections.Generic;\nusing System.Linq;\nusing System.Text;\n\nnamespace ConsoleApplication\n{\n class Program\n {\n public static void Main(string[] args)\n {\n var s = Console.ReadLine();\n var l = new List<int>();\n var r = new List<int>();\n var i = 0;\n foreach (char c in s)\n {\n i++;\n if(c=='l')\n {\n r.Add(i);\n }\n else\n {\n l.Add(i);\n }\n }\n foreach (int i12 in l)\n {\n Console.WriteLine(i12);\n }\n r.Reverse();\n foreach (int i2 in r)\n {\n Console.WriteLine(i2);\n }\n }\n }\n}\n\n</code></pre><p>In one of Java solutions I've seen class "FastScanner" with only method "FastRead", which reads from STDIO. If you think that the time issue is in IO, maybe there is a possibility to write some wrappers aroung Ruby's gets and puts? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119343 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119343 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119343\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119360\" commentParentId=\"119343\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119360\" href=\"?#comment-119360\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119343\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119360\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119360\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't now C# well but I think <code>WriteLine</code> method flushes the output. I inserted a hack into your solution and it passed: <a href=\"/contest/264/submission/2981286\" title=\"Submission 2981286 by dalex\">2981286</a></p><p>But it's better to write your own input/output class. I know user <a class=\"rated-user user-orange\" href=\"/profile/it4.kp\" title=\"Master it4.kp\">it4.kp</a> uses C# — look over his submissions.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119360 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119360 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119360\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119368\" commentParentId=\"119360\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119368\" href=\"?#comment-119368\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119360\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119368\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119368\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow, your advice is EXTREMELY useful! Thank you.</p><p>I have tried same in Ruby, and now it fails on 45th, not 31st test. I just replaced that <code>puts left</code> with puts <code>left.join("\\n")</code>, and the perfomance went up dramaticly. So, it seems that the weakest part in Ruby is the IO. Will think about it more.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119368 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119368 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119368\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119370\" commentParentId=\"119343\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:35\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119370\" href=\"?#comment-119370\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119343\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119370\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119370\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119370\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello. Just use StringBuilder. But don't forget that it uses a lot of memory. Example:<a href=\"https://codeforces.com/contest/265/submission/2974651\">http://codeforces.com/contest/265/submission/2974651</a> Also you can use a small buffer: <a href=\"https://codeforces.com/contest/265/submission/2974575\">http://codeforces.com/contest/265/submission/2974575</a> That is <a class=\"rated-user user-orange\" href=\"/profile/eduardische\" title=\"Master eduardische\">eduardische</a>'s advice. And.. Console.Write() works faster than Console.WriteLine(). <a href=\"https://codeforces.com/contest/265/submission/2973339\">http://codeforces.com/contest/265/submission/2973339</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119370 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119370 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119370\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:43\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119371\" href=\"?#comment-119371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can't view images from the problem Div1 D: 403 forbitten. :-(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119374\" commentParentId=\"119371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rng_58\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/733/avatar/12337379adfa9a4c.jpg'/> </a>\n <div><a href=\"/profile/rng_58\" title=\"Legendary Grandmaster rng_58\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">r</span>ng_58</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119374\" href=\"?#comment-119374\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119374\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119374\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fixed now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119374 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119374 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119374\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121846\" commentParentId=\"119374\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/11/2013 15:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121846\" href=\"?#comment-121846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119374\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems in problem D should be "A = c1c2c1c2..., C = c2c1c2c1." instead of "A = c1c2c1c2..., B = c2c1c2c1." And further should be C instead of B.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121846\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119379\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jill-jenn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/61244/avatar/379a15a12e1d32c7.jpg'/> </a>\n <div><a href=\"/profile/jill-jenn\" title=\"Expert jill-jenn\" class=\"rated-user user-blue\">jill-jenn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 02:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119379\" href=\"?#comment-119379\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119379\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119379\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"61244\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119379\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I assume you meant “when <em>i</em> is a <em>divisor</em> of <em>x</em>” instead of “when <em>i</em> is a <em>multiple</em> of <em>x</em>.”, in Good Sequences.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119379 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119379 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119379\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119385\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hupmscy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/26636/avatar/20574dd78ad48c95.jpg'/> </a>\n <div><a href=\"/profile/hupmscy\" title=\"Specialist hupmscy\" class=\"rated-user user-cyan\">hupmscy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:03\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119385\" href=\"?#comment-119385\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119385\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"26636\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119385\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div2 D Good Sequences, I don't understand why the sum of the number of the diviser from 1 to n is O(nlogn). Can someone prove it? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119385 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119385 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119385\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119391\" commentParentId=\"119385\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nishant4\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/nishant4\" title=\"Candidate Master nishant4\" class=\"rated-user user-violet\">nishant4</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:24\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119391\" href=\"?#comment-119391\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119385\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119391\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"57571\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119391\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let p be a number in the range 1 — n Now, p will divide n/p no.s Sum of no. of divisors — {Summation(p = 1 to n)} n/p <= n * {Summation(p = 1 to n)} 1/p = n * H(n) ( H is sum of harmonic series ) and since ln(n) < H(n) < ln(n) + 1 thus, n * ln(n) < Answer < n * (ln(n) + 1)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119391 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119391 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119391\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119388\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Martuza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12501/avatar/b25fe2e78d5c1ec.jpg'/> </a>\n <div><a href=\"/profile/Martuza\" title=\"Pupil Martuza\" class=\"rated-user user-green\">Martuza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:23\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119388\" href=\"?#comment-119388\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119388\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119388\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"12501\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119388\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 A / Div2 C Escape from Stones (Author: DEGwer) :</p><p>My solution is in O(2n), But code is so simple like it,</p> <pre><code>int main(){\n\tstring a;\n\tcin>>a;\n\tfor(long i=0; i<a.size(); i++)\n\tif(a[i]=='r') cout<<i+1<<endl;\n\t\t\n\tfor(long i=a.size()-1; i>=0; i--)\n\tif(a[i]=='l') cout<<i+1<<endl;\n\t\n return 0;\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119388 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119388 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119388\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"136294\" commentParentId=\"119388\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/moji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/80646/avatar/7b6fe780caa2c87c.jpg'/> </a>\n <div><a href=\"/profile/moji\" title=\"Candidate Master moji\" class=\"rated-user user-violet\">moji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2013 10:35\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-136294\" href=\"?#comment-136294\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119388\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"136294\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"136294\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"80646\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-136294\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>nice! But actually O(2n) = O(n) by the definition.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-136294 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-136294 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-136294\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120163\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Calvinxiao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Calvinxiao\" title=\"Expert Calvinxiao\" class=\"rated-user user-blue\">Calvinxiao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 09:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120163\" href=\"?#comment-120163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"54647\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 A/Div2 C</p><p><code>Finally, you should print the integers in the first vector by default order, after that, you should print the integers in the second vector in the reverse order.</code></p><p>should be: Finally, you should print the integers in the <strong>second</strong> vector by default order, after that, you should print the integers in the <strong>first</strong> vector in the reverse order.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120163\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Prestige\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19197/avatar/cf8ba2c2433b97.jpg'/> </a>\n <div><a href=\"/profile/Prestige\" title=\"Pupil Prestige\" class=\"rated-user user-green\">Prestige</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 14:30\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120170\" href=\"?#comment-120170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120170\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-11\"\r\n data-commentUserId=\"19197\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>2 problems of 7 are made by round author)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"214721\" commentParentId=\"120170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/catlak_profesor_mfb\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128467/avatar/81a7af0e3b8fb3f0.jpg'/> </a>\n <div><a href=\"/profile/catlak_profesor_mfb\" title=\"Candidate Master catlak_profesor_mfb\" class=\"rated-user user-violet\">catlak_profesor_mfb</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/25/2015 01:23\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-214721\" href=\"?#comment-214721\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"214721\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"128467\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-214721\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So what?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-214721 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-214721 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-214721\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"244903\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/OmaeWaMouShenDeiru\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88303/avatar/2756cc1cc5d9a15c.jpg'/> </a>\n <div><a href=\"/profile/OmaeWaMouShenDeiru\" title=\"Pupil OmaeWaMouShenDeiru\" class=\"rated-user user-green\">OmaeWaMouShenDeiru</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/10/2015 12:31\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-244903\" href=\"?#comment-244903\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"244903\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"88303\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-244903\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved DIV 2 C by looking at the input and output, I never understood the problem statement !! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-244903 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-244903 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-244903\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"251734\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ananth94\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/211746/avatar/72fbf14db6a1bcdc.jpg'/> </a>\n <div><a href=\"/profile/ananth94\" title=\"Specialist ananth94\" class=\"rated-user user-cyan\">ananth94</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2015 21:38\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-251734\" href=\"?#comment-251734\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"251734\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"211746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-251734\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could someone explain DIV1-C in more detail? Thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-251734 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-251734 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-251734\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"286092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/divyank1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143482/avatar/3da31c0aab0a7196.jpg'/> </a>\n <div><a href=\"/profile/divyank1\" title=\"Specialist divyank1\" class=\"rated-user user-cyan\">divyank1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/26/2016 16:46\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-286092\" href=\"?#comment-286092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"286092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143482\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-286092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div2 C <em>Escape from Stones</em> can also be solved using <em>Doubly Linked Lists</em>.</p><p>Maintain a pointer <code>operatingPointer</code> which is initialized to the <code>head</code> of list (head of the list contains 1).</p><p>if we encounter 'l' at <code>ith</code> position of input add i+1 to the <code>left</code> of <code>operatingPointer</code> and update <code>operatingPointer</code> to newly created node.</p><p>Similarly if we encounter 'r' at <code>ith</code> position of the string add i+1 to the <code>right</code> of <code>operatingPointer</code> and update <code>operatingPointer</code> to newly created node.</p><p>Then print the whole list.</p><p><a href=\"//codeforces.com/contest/264/submission/16956916\">Implementation using Doubly Linked Lists</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-286092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-286092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-286092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"296233\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/szawinis\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/413991/avatar/77a65dc71d2f7f59.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/szawinis\" title=\"Candidate Master szawinis\" class=\"rated-user user-violet\">szawinis</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/28/2016 05:41\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-296233\" href=\"?#comment-296233\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"296233\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"413991\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-296233\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2 D/ Div 1 B, why do we have to update d[i] for all divisors of x? Can someone explain? Thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-296233 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-296233 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-296233\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"640442\" commentParentId=\"296233\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbhishekAg\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/AbhishekAg\" title=\"Expert AbhishekAg\" class=\"rated-user user-blue\">AbhishekAg</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2020 13:23\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-640442\" href=\"?#comment-640442\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-296233\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"640442\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"826040\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-640442\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Getting wrong answer for test 13 in div1 b......Can someone explain what is wrong in <a href=\"https://codeforces.com/problemset/submission/264/83518635\">this</a>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-640442 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-640442 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-640442\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"301587\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/HalfBloodPrince\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/332453/avatar/a1a516d280a7dbef.jpg'/> </a>\n <div><a href=\"/profile/HalfBloodPrince\" title=\"Expert HalfBloodPrince\" class=\"rated-user user-blue\">HalfBloodPrince</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/21/2016 18:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-301587\" href=\"?#comment-301587\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"301587\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"301587\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"332453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-301587\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could a top-down approach be used for div1 B/div2 D? I tried a top down approach but I am not able to memoize it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-301587 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-301587 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-301587\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310750\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/red_dust\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/417513/avatar/d7a2f654b2949853.jpg'/> </a>\n <div><a href=\"/profile/red_dust\" title=\"Expert red_dust\" class=\"rated-user user-blue\">red_dust</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/19/2016 11:02\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310750\" href=\"?#comment-310750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"417513\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div A/Div2 C Escape from Stones the algorithm is easy to understand if someone explains it,</p><p>but I don't understand how this solution came to be, which trail of thought led to this solution.</p><p>can someone please explain it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"331390\" commentParentId=\"310750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marlonbymendes\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/358576/avatar/a4da054df60816b9.jpg'/> </a>\n <div><a href=\"/profile/marlonbymendes\" title=\"Expert marlonbymendes\" class=\"rated-user user-blue\">marlonbymendes</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/18/2016 00:15\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-331390\" href=\"?#comment-331390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-310750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"331390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"358576\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-331390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Read my comment below.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-331390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-331390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-331390\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"331388\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marlonbymendes\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/358576/avatar/a4da054df60816b9.jpg'/> </a>\n <div><a href=\"/profile/marlonbymendes\" title=\"Expert marlonbymendes\" class=\"rated-user user-blue\">marlonbymendes</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/18/2016 00:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-331388\" href=\"?#comment-331388\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"331388\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"358576\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-331388\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think editorial nor comments explanation on solution <a href=\"/contest/264/problem/A\" title=\"Codeforces Round 162 (Div. 1)\">264A - Escape from Stones</a> are intuitive so I'll try to explain how I came up with a solution. </p><p>You can visualize the problem as a binary tree. Each node is responsable for a interval <strong>[a, b]</strong>. Starting from the root, responsable for <strong>[0, 1]</strong>, if you go left then root will have a left child responsable for interval <strong>[0, 1 / 2]</strong>. Since you're a left child, last time the stone fell on position 1 / 2, the end point of the interval.</p><p>Note that from that child, it doesn't matter if you go left or right: the stone will never fall on a position bigger than 1 / 2 (the end point). The ideia is: since a stone always fall on the midpoint <strong>(a + b) / 2</strong> of the lower and end points, it can never fall after the endpoint. In fact, the stone must fall infinitely many times to the right to reach that endpoint. So, we were on a node [0, 1], the stone fell and we jumped to the left, creating a left child [0, 1 / 2] and we now know that there is no way the stone will every fall to a position > 1 / 2. This means that in the final solution, the current node [0, 1 / 2] will come AFTER all nodes (descendents) that come after this one.</p><p>If we jumped to the right instead, creating a right child responsable for interval [1 / 2, 1] we can show the same way that the stone will never fall before the starting point 1 / 2. This means that the current node will com BEFORE all nodes (descendents) that come after this one, since we know that the stone can't fall on a postion < 1 / 2 from now on.</p><p>This is an algorithm: if in the i'th stone we jumped to the left, we now that stone i will become AFTER all next stones. If we jumped right, stone i will become BEFORE all next stones.</p><p>Code: <a href=\"/contest/264/submission/23071895\" title=\"Submission 23071895 by marlonbymendes\">23071895</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-331388 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-331388 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-331388\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"386173\" commentParentId=\"331388\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ameyanator\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/464121/avatar/e34f7dc2b59a7b4c.jpg'/> </a>\n <div><a href=\"/profile/ameyanator\" title=\"Specialist ameyanator\" class=\"rated-user user-cyan\">ameyanator</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/18/2017 10:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-386173\" href=\"?#comment-386173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-331388\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"386173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"464121\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-386173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Awesome explanation thanks! :')</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-386173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-386173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-386173\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360590\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/the_an0nym0us\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/303591/avatar/41fc9495b1ea2f27.jpg'/> </a>\n <div><a href=\"/profile/the_an0nym0us\" title=\"Specialist the_an0nym0us\" class=\"rated-user user-cyan\">the_an0nym0us</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/17/2017 08:56\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360590\" href=\"?#comment-360590\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360590\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"303591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360590\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Strange! My C++ code got accepted with printf but got TLE with cout. This is too harsh</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360590 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360590 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360590\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360690\" commentParentId=\"360590\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/559880/avatar/fd0565aa541e0d1.jpg'/> </a>\n <div><a href=\"/profile/Guy\" title=\"Candidate Master Guy\" class=\"rated-user user-violet\">Guy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/18/2017 10:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360690\" href=\"?#comment-360690\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-360590\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"360690\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"360690\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"559880\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360690\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>printf is faster than cout. if u want to use cout its better type ios::sync_with_stdio(false),cin.tie(0),cout.tie(0); in your code this make cout fast</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360690 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360690 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360690\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"365999\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akhi29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207626/avatar/c39a3ca998f53094.jpg'/> </a>\n <div><a href=\"/profile/akhi29\" title=\"Pupil akhi29\" class=\"rated-user user-green\">akhi29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2017 01:33\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-365999\" href=\"?#comment-365999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"365999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"365999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207626\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-365999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm unable to solve Escape from Stones in java. In spite of using fast io, it always gives me a TLE now matter how much i optimize it <a href=\"//codeforces.com/contest/264/submission/27712057\">sol</a> did anyone get it AC in java?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-365999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-365999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-365999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"385333\" commentParentId=\"365999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zodiacleo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/zodiacleo\" title=\"Pupil zodiacleo\" class=\"rated-user user-green\">zodiacleo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2017 11:29\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-385333\" href=\"?#comment-385333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-365999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"385333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"145879\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-385333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi <a class=\"rated-user user-green\" href=\"/profile/akhi29\" title=\"Pupil akhi29\">akhi29</a><br />Two points-<br />1. Try to use <code>StringBuilder</code> (popular practice among Java user's) instead of directly printing to the output console.<br />2. When you call, <code>close()</code> of <code>PrintStream</code>, it isn't obliged to flush your output to the console. You need to call <code>flush()</code> explicitly to ensure that the data, if present in the buffer is flushed to the output console. You can refer the modified submission <a href=\"/contest/264/submission/30322735\" title=\"Submission 30322735 by zodiacleo\">30322735</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-385333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-385333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-385333\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587566\" commentParentId=\"385333\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akhi29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207626/avatar/c39a3ca998f53094.jpg'/> </a>\n <div><a href=\"/profile/akhi29\" title=\"Pupil akhi29\" class=\"rated-user user-green\">akhi29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 01:45\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587566\" href=\"?#comment-587566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-385333\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207626\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks zodiacleo</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"379370\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Target2018\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/295556/avatar/f6fe0b640b7fee7.jpg'/> </a>\n <div><a href=\"/profile/Target2018\" title=\"Newbie Target2018\" class=\"rated-user user-gray\">Target2018</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/18/2017 18:55\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-379370\" href=\"?#comment-379370\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"379370\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"295556\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-379370\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In <a href=\"//codeforces.com/contest/265/problem/C\">DIV 2 C</a> I took 2 variables hi = 1 and lo = 0, if character is 'l' then I just change hi = (hi + lo) / 2 otherwise lo = (hi + lo) / 2 and mapped the value, sort them and print them, but got WA on Testcase 11, could you please tell me what is I'm missing?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-379370 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-379370 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-379370\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"384618\" commentParentId=\"379370\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bibhuti\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/561745/avatar/eb1f97e82517cf9e.jpg'/> </a>\n <div><a href=\"/profile/Bibhuti\" title=\"Specialist Bibhuti\" class=\"rated-user user-cyan\">Bibhuti</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/07/2017 19:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-384618\" href=\"?#comment-384618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-379370\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"384618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"561745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-384618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I hope it may be because of the precision problem. I am also facing the same and below is my solution</p><p><a href=\"/contest/264/submission/30185936\" title=\"Submission 30185936 by Bibhuti\">30185936</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-384618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-384618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-384618\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"396488\" commentParentId=\"384618\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/neroond\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/375945/avatar/2a26526cf4420757.jpg'/> </a>\n <div><a href=\"/profile/neroond\" title=\"Expert neroond\" class=\"rated-user user-blue\">neroond</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/21/2017 13:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-396488\" href=\"?#comment-396488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-384618\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"396488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"375945\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-396488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in DIV2 D what will be answer in case 5 : 2 4 8 6 9. My solution that got AC. outputs 5, but how? 8 is bigger than 6 they can't form a sequence </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-396488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-396488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-396488\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"411637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sabertooth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/547698/avatar/2106fe4acab8cfe4.jpg'/> </a>\n <div><a href=\"/profile/sabertooth\" title=\"Specialist sabertooth\" class=\"rated-user user-cyan\">sabertooth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2018 07:14\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-411637\" href=\"?#comment-411637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"411637\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"411637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"547698\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-411637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In <strong>Div 1 A</strong> Stones falls in 'k' position and print the stone position from left</p><p>I calculated 'k' and 'd' as k=(X+Y)/2 and d=(Y-X)/2 And if 'l' then x-=d otherwise y+=d. then sorted the array which contains 'k' s value and its position no. but my implementation isn't matching with the test case..</p><p>Did I misunderstood the ques or my idea is wrong?</p><p><a href=\"https://paste.ubuntu.com/26503881/\">CODE</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-411637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-411637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-411637\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"453240\" commentParentId=\"411637\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wallcrawler\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/446649/avatar/28b029f94566d9b0.jpg'/> </a>\n <div><a href=\"/profile/wallcrawler\" title=\"Expert wallcrawler\" class=\"rated-user user-blue\">wallcrawler</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/22/2018 10:35\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-453240\" href=\"?#comment-453240\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-411637\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"453240\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"446649\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-453240\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The thing is that, suppose you only go left then it means that the stones would be at 1/2,1/4,1/8,...till 1/(2^(10^6)) (considering maximum length of the string) which can't be stored in the float value.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-453240 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-453240 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-453240\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469926\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/umangahuja1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/480801/avatar/6a0f8d27102d0ec0.jpg'/> </a>\n <div><a href=\"/profile/umangahuja1\" title=\"Expert umangahuja1\" class=\"rated-user user-blue\">umangahuja1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 11:09\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469926\" href=\"?#comment-469926\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"469926\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"480801\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469926\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For those facing TLE in the problem Div1 A (Div2 C Escape from Stones) in C++ even with <code>O(N)</code> time complexity the reason can be <code>endl vs '\\n'</code>.</p><p><code>'\\n</code>' inserts a new line to the output stream while</p><p><code>endl</code> inserts a new line as well as flushes the output stream.</p><p>So using <code>'\\n'</code>can solve the TLE issue.</p><p>Also you can use fast IO with cin/cout too instead of using scanf/printf by adding these lines in your code.</p><p><code>ios::sync_with_stdio(false);</code></p><p><code>cin.tie(0);</code></p><p><code>cout.tie(0);</code></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469926 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469926 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469926\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"494267\" commentParentId=\"469926\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SohrabRoohi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SohrabRoohi\" title=\"Specialist SohrabRoohi\" class=\"rated-user user-cyan\">SohrabRoohi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/22/2019 01:54\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-494267\" href=\"?#comment-494267\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-469926\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"494267\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"620634\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-494267\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Believe it or not this actually solved the problem for me. I was using a linked list and basically pushing to the front and back and was confused how I was getting TLE with 1,000,000 O(1) operations. I ended up writing my own code for a linked list and still failed case 31, changing the endl to \\n made it accepted. This made it go from 2000 ms TLE to 233 ms, thank you for your post.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-494267 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-494267 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-494267\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512701\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pseudocoder10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/pseudocoder10\" title=\"Master pseudocoder10\" class=\"rated-user user-orange\">pseudocoder10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2019 15:13\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512701\" href=\"?#comment-512701\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"512701\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"512701\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"786409\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512701\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved div1A using a binary tree, if character is l then i add to the left of parent node otherwise i add to the right, then an inorder traversal will give the answer but im getting TLE at testcase 31 idk why since my code is implemented in O(n) complexity. My solution(<a href=\"https://codeforces.com/contest/264/submission/54413614\">https://codeforces.com/contest/264/submission/54413614</a>)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512701 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512701 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512701\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"553043\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wolfie.\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/889894/avatar/b1389c1ceb58933b.jpg'/> </a>\n <div><a href=\"/profile/wolfie.\" title=\"Expert wolfie.\" class=\"rated-user user-blue\">wolfie.</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2019 17:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-553043\" href=\"?#comment-553043\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"553043\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"553043\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"889894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-553043\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Something is wrong with the testing of the question Div 1(A)/ Div2(C) . Got 2 TLE's on a O(n) solution [Test Case 31] , changed endl and to '\\n' and then got runtime error on test 41. </p><p>TLE — <a href=\"https://codeforces.com/contest/265/submission/63245660\">https://codeforces.com/contest/265/submission/63245660</a> Runtime Error — <a href=\"https://codeforces.com/contest/265/submission/63246396\">https://codeforces.com/contest/265/submission/63246396</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-553043 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-553043 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-553043\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621308\" commentParentId=\"553043\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/UNOwen98\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/UNOwen98\" title=\"Expert UNOwen98\" class=\"rated-user user-blue\">UNOwen98</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 09:56\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621308\" href=\"?#comment-621308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-553043\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1254135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am facing the same problem. Were you able to fix it ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621308\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621403\" commentParentId=\"621308\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wolfie.\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/889894/avatar/b1389c1ceb58933b.jpg'/> </a>\n <div><a href=\"/profile/wolfie.\" title=\"Expert wolfie.\" class=\"rated-user user-blue\">wolfie.</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621403\" href=\"?#comment-621403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-621308\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"889894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, i kept on getting runtime error with that approach.. so i changed my implementation a little bit, and it got accepted. <a href=\"https://codeforces.com/contest/265/submission/63246871\">Accepted Solution.</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621435\" commentParentId=\"621403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/UNOwen98\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/UNOwen98\" title=\"Expert UNOwen98\" class=\"rated-user user-blue\">UNOwen98</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 13:39\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621435\" href=\"?#comment-621435\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-621403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621435\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"1254135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621435\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I had to do this too. I guess the problem was caused because the second loop ( which is being run backwards ) was trying to access some invalid memory. The problems gets fixed when the array is reversed and loop is run forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621435 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621435 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621435\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"664098\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iabhishek15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1226114/avatar/6ce33a9f7d454deb.jpg'/> </a>\n <div><a href=\"/profile/iabhishek15\" title=\"Expert iabhishek15\" class=\"rated-user user-blue\">iabhishek15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2020 19:31\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-664098\" href=\"?#comment-664098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"664098\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"664098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1226114\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-664098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an another approach for div1B. for each number check the maxm times a divisor has occurred from all the divisors of a number and then increase the maxm by 1 and iterate again and update all the divisors</p><p>code <a href=\"/contest/264/submission/87253298\" title=\"Submission 87253298 by iabhishek15\">87253298</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-664098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-664098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-664098\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1035696\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ahmed_ElGendy56\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2725312/avatar/e34f70ed817bafea.jpg'/> </a>\n <div><a href=\"/profile/Ahmed_ElGendy56\" title=\"Pupil Ahmed_ElGendy56\" class=\"rated-user user-green\">Ahmed_ElGendy56</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/07/2023 19:42\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1035696\" href=\"?#comment-1035696\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1035696\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-7\"\r\n data-commentUserId=\"2725312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1035696\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you are using C++ for solving (Div1 A / Div2 C Escape from Stones) and got a TLE error on the 31st test you have to be sure you are using ("\\n") instead of (endl) because (endl) takes more time for flushing.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1035696 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1035696 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1035696\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046784\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/oishi_161\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2006012/avatar/8428423d6c055dae.jpg'/> </a>\n <div><a href=\"/profile/oishi_161\" title=\"Newbie oishi_161\" class=\"rated-user user-gray\">oishi_161</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 11:18\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046784\" href=\"?#comment-1046784\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046784\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2006012\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046784\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem div2 B in more detail?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046784 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1046784 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1046784\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046792\" commentParentId=\"1046784\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SummerSky\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/419016/avatar/8ddf3c5c2dc6bf44.jpg'/> </a>\n <div><a href=\"/profile/SummerSky\" title=\"Expert SummerSky\" class=\"rated-user user-blue\">SummerSky</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 11:36\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046792\" href=\"?#comment-1046792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-1046784\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"419016\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Note that we can only move to the next tree, but not to the previous one. So, to eat all the nuts, we must start from the first tree and visit one by one until we reach the final one. When we are on the top of some tree-i (because we must go to the top to eat that nut), and eat the nut, then we should move to the next tree. If next tree has lower height, we have to move down to the same height and then jump (to save time). Otherwise, we can directly jump to the next tree (also to save time). </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1046792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1046792\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046818\" commentParentId=\"1046792\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/oishi_161\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2006012/avatar/8428423d6c055dae.jpg'/> </a>\n <div><a href=\"/profile/oishi_161\" title=\"Newbie oishi_161\" class=\"rated-user user-gray\">oishi_161</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 12:46\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046818\" href=\"?#comment-1046818\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-1046792\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046818\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2006012\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046818\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for your help.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046818 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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Choosing Balls"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Choosing Balls</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There are <span class=\"tex-span\"><i>n</i></span> balls. They are arranged in a row. Each ball has a color (for convenience an integer) and an integer value. The color of the <span class=\"tex-span\"><i>i</i></span>-th ball is <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> and the value of the <span class=\"tex-span\"><i>i</i></span>-th ball is <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Squirrel Liss chooses some balls and makes a new sequence without changing the relative order of the balls. She wants to maximize the value of this sequence.</p><p>The value of the sequence is defined as the sum of following values for each ball (where <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> are given constants):</p><ul> <li> If the ball is not in the beginning of the sequence and the color of the ball is same as previous ball's color, add (the value of the ball) <span class=\"tex-span\"> × </span> <span class=\"tex-span\"><i>a</i></span>. </li><li> Otherwise, add (the value of the ball) <span class=\"tex-span\"> × </span> <span class=\"tex-span\"><i>b</i></span>. </li></ul><p>You are given <span class=\"tex-span\"><i>q</i></span> queries. Each query contains two integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>. For each query find the maximal value of the sequence she can make when <span class=\"tex-span\"><i>a</i> = <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i> = <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Note that the new sequence can be <span class=\"tex-font-style-bf\">empty</span>, and the value of an empty sequence is defined as zero.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>q</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>; 1 ≤ <i>q</i> ≤ 500</span>). The second line contains <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub>, <i>v</i><sub class=\"lower-index\">2</sub>, ..., <i>v</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">|<i>v</i><sub class=\"lower-index\"><i>i</i></sub>| ≤ 10<sup class=\"upper-index\">5</sup></span>). The third line contains <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">1</sub>, <i>c</i><sub class=\"lower-index\">2</sub>, ..., <i>c</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>).</p><p>The following <span class=\"tex-span\"><i>q</i></span> lines contain the values of the constants <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> for queries. The <span class=\"tex-span\"><i>i</i></span>-th of these lines contains two integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">|<i>a</i><sub class=\"lower-index\"><i>i</i></sub>|, |<i>b</i><sub class=\"lower-index\"><i>i</i></sub>| ≤ 10<sup class=\"upper-index\">5</sup></span>).</p><p>In each line integers are separated by single spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query, output a line containing an integer — the answer to the query. The <span class=\"tex-span\"><i>i</i></span>-th line contains the answer to the <span class=\"tex-span\"><i>i</i></span>-th query in the input order.</p><p>Please, do not write the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6 3<br/>1 -2 3 4 0 -1<br/>1 2 1 2 1 1<br/>5 1<br/>-2 1<br/>1 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>20<br/>9<br/>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 1<br/>-3 6 -1 2<br/>1 2 3 1<br/>1 -1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, to achieve the maximal value:</p><ul> <li> In the first query, you should select 1st, 3rd, and 4th ball. </li><li> In the second query, you should select 3rd, 4th, 5th and 6th ball. </li><li> In the third query, you should select 2nd and 4th ball. </li></ul><p>Note that there may be other ways to achieve the maximal value.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"c601e4a2bd2495631750a2e59ad44b75\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"19843d15aee6a49b49ab812b3433503e5e4f1193\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Choosing Balls</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There are <span class=\"tex-span\"><i>n</i></span> balls. They are arranged in a row. Each ball has a color (for convenience an integer) and an integer value. The color of the <span class=\"tex-span\"><i>i</i></span>-th ball is <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> and the value of the <span class=\"tex-span\"><i>i</i></span>-th ball is <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Squirrel Liss chooses some balls and makes a new sequence without changing the relative order of the balls. She wants to maximize the value of this sequence.</p><p>The value of the sequence is defined as the sum of following values for each ball (where <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> are given constants):</p><ul> <li> If the ball is not in the beginning of the sequence and the color of the ball is same as previous ball's color, add (the value of the ball) <span class=\"tex-span\"> × </span> <span class=\"tex-span\"><i>a</i></span>. </li><li> Otherwise, add (the value of the ball) <span class=\"tex-span\"> × </span> <span class=\"tex-span\"><i>b</i></span>. </li></ul><p>You are given <span class=\"tex-span\"><i>q</i></span> queries. Each query contains two integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>. For each query find the maximal value of the sequence she can make when <span class=\"tex-span\"><i>a</i> = <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i> = <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Note that the new sequence can be <span class=\"tex-font-style-bf\">empty</span>, and the value of an empty sequence is defined as zero.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>q</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>; 1 ≤ <i>q</i> ≤ 500</span>). The second line contains <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>v</i><sub class=\"lower-index\">1</sub>, <i>v</i><sub class=\"lower-index\">2</sub>, ..., <i>v</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">|<i>v</i><sub class=\"lower-index\"><i>i</i></sub>| ≤ 10<sup class=\"upper-index\">5</sup></span>). The third line contains <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\">1</sub>, <i>c</i><sub class=\"lower-index\">2</sub>, ..., <i>c</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>).</p><p>The following <span class=\"tex-span\"><i>q</i></span> lines contain the values of the constants <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> for queries. The <span class=\"tex-span\"><i>i</i></span>-th of these lines contains two integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">|<i>a</i><sub class=\"lower-index\"><i>i</i></sub>|, |<i>b</i><sub class=\"lower-index\"><i>i</i></sub>| ≤ 10<sup class=\"upper-index\">5</sup></span>).</p><p>In each line integers are separated by single spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query, output a line containing an integer — the answer to the query. The <span class=\"tex-span\"><i>i</i></span>-th line contains the answer to the <span class=\"tex-span\"><i>i</i></span>-th query in the input order.</p><p>Please, do not write the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in С++. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6 3<br />1 -2 3 4 0 -1<br />1 2 1 2 1 1<br />5 1<br />-2 1<br />1 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>20<br />9<br />4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 1<br />-3 6 -1 2<br />1 2 3 1<br />1 -1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example, to achieve the maximal value:</p><ul> <li> In the first query, you should select 1st, 3rd, and 4th ball. </li><li> In the second query, you should select 3rd, 4th, 5th and 6th ball. </li><li> In the third query, you should select 2nd and 4th ball. </li></ul><p>Note that there may be other ways to achieve the maximal value.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='4298c77d77d8d2562e182e69f443373f'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" 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user-legendary\"><span class=\"legendary-user-first-letter\">r</span>ng_58</a>,\r\n <span class=\"format-humantime\" title=\"Jan/21/2013 18:21\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h4><a href=\"//codeforces.com/problemset/problem/265/A\">Div2 A Colorful Stones (Simplified Edition)</a> (Author: <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>)</h4><p>In this problem you just need to implement what is written in the statement. Make a variable that holds the position of Liss, and simulate the instructions one by one.</p><h4><a href=\"//codeforces.com/problemset/problem/265/B\">Div2 B Roadside Trees (Simplified Edition)</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/snuke\" title=\"Expert snuke\">snuke</a>)</h4><p>The optimal path of Liss is as follows: First she starts from the root of tree 1. Walk up the tree to the top and eat a nut. Walk down to the height <span class=\"tex-span\"><i>min</i>(<i>h</i><sub class=\"lower-index\">1</sub>, <i>h</i><sub class=\"lower-index\">2</sub>)</span>. Jump to the tree 2. Walk up the tree to the top and eat a nut. Walk down to the height <span class=\"tex-span\"><i>min</i>(<i>h</i><sub class=\"lower-index\">2</sub>, <i>h</i><sub class=\"lower-index\">3</sub>)</span>, <span class=\"tex-span\">...</span> and so on.</p><h4><a href=\"//codeforces.com/problemset/problem/264/A\">Div1 A / Div2 C Escape from Stones</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/DEGwer\" title=\"Expert DEGwer\">DEGwer</a>)</h4><p>In this problem, there are many simple algorithms which works in <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. One of them (which I intended) is following:</p><p>You should prepare 2 vectors. If <span class=\"tex-span\"><i>s</i>[<i>i</i>] = '<i>l</i>'</span>, you should push i to the first vector, and if <span class=\"tex-span\"><i>s</i>[<i>i</i>] = '<i>r</i>'</span>, you should push i to the second vector. Finally, you should print the integers in the second vector by default order, after that, you should print the integers in the first vector in the reverse order.</p><p>This algorithm works because if Liss divides an interval into two intervals <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> and she enters <span class=\"tex-span\"><i>A</i></span>, she will never enter <span class=\"tex-span\"><i>B</i></span>.</p><h4><a href=\"//codeforces.com/problemset/problem/264/B\">Div1 B / Div2 D Good Sequences</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/DEGwer\" title=\"Expert DEGwer\">DEGwer</a>)</h4><p>The main idea is DP. Let's define <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> as the maximal value of the length of the good sequence whose last element is <span class=\"tex-span\"><i>x</i></span>, and define <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> as the (maximal value of <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> where <span class=\"tex-span\"><i>x</i></span> is divisible by <span class=\"tex-span\"><i>i</i></span>).</p><p>You should calculate <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> in the increasing order of x. The value of <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span> is (maximal value of <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> where <span class=\"tex-span\"><i>i</i></span> is a divisor of <span class=\"tex-span\"><i>x</i></span>) + 1. After you calculate <span class=\"tex-span\"><i>dp</i>[<i>x</i>]</span>, for each divisor <span class=\"tex-span\"><i>i</i></span> of <span class=\"tex-span\"><i>x</i></span>, you should update <span class=\"tex-span\"><i>d</i>[<i>i</i>]</span> too.</p><p>This algorithm works in <span class=\"tex-span\"><i>O</i>(<i>nlogn</i>)</span> because the sum of the number of the divisor from 1 to <span class=\"tex-span\"><i>n</i></span> is <span class=\"tex-span\"><i>O</i>(<i>nlogn</i>)</span>.</p><p>Note that there is a corner case. When the set is <span class=\"tex-span\">{1}</span>, you should output 1.</p><h4><a href=\"//codeforces.com/problemset/problem/264/C\">Div1 C / Div2 E Choosing Balls</a> (Author: <a class=\"rated-user user-orange\" href=\"/profile/hogloid\" title=\"Master hogloid\">hogloid</a>)</h4><p>There are many <span class=\"tex-span\"><i>O</i>(<i>Q</i> * <i>N</i> * <i>logN</i>)</span> solutions using segment trees or other data structures, but probably they will get time limit exceeded.</p><p>We can solve each query independently. First, let's consider the following DP algorithm.</p><p><span class=\"tex-span\"><i>dp</i>[<i>c</i>]</span> := the maximal value of a sequence whose last ball's color is <span class=\"tex-span\"><i>c</i></span></p><p>For each ball <span class=\"tex-span\"><i>i</i></span>, we want to update the array. Let the <span class=\"tex-span\"><i>i</i></span>-th ball's color be <span class=\"tex-span\"><i>col</i>[<i>i</i>]</span>, the <span class=\"tex-span\"><i>i</i></span>-th ball's value be <span class=\"tex-span\"><i>val</i>[<i>i</i>]</span>, and the maximal value of dp array other than <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> be <span class=\"tex-span\"><i>otherMAX</i></span>. We can update the value of <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> to <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]] + <i>val</i>[<i>i</i>] × <i>a</i></span> or <span class=\"tex-span\"><i>otherMAX</i> + <i>val</i>[<i>i</i>] × <i>b</i></span>. Here, we only need to know <span class=\"tex-span\"><i>dp</i>[<i>col</i>[<i>i</i>]]</span> and <span class=\"tex-span\"><i>otherMAX</i></span>. If we remember the biggest two values of <span class=\"tex-span\"><i>dp</i></span> array in that time and their indexes in the array, <span class=\"tex-span\"><i>otherMAX</i></span> can be calculated using the biggest two values, which always include maximal values of dp array other than any particular color.</p><p>Since the values of dp array don't decrease, we can update the biggest two values in <span class=\"tex-span\"><i>O</i>(1)</span>. Finally, the answer for the query is the maximal value of <span class=\"tex-span\"><i>dp</i></span> array.</p><p>The complexity of the described algorithm is <span class=\"tex-span\"><i>O</i>(<i>QN</i>)</span>.</p><h4><a href=\"//codeforces.com/problemset/problem/264/D\">Div1 D Colorful Stones</a> (Author: <a class=\"rated-user user-red\" href=\"/profile/rng_58\" title=\"International Grandmaster rng_58\">rng_58</a>)</h4><p>First, let's consider a simpler version of the problem: You are given a start state and a goal state. Check whether the goal state is reachable from the start state.</p><p>Define <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span>, <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>D</i></span> as in the picture below, and let <span class=\"tex-span\"><i>I</i></span> be the string of your instructions. <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are substrings of <span class=\"tex-span\"><i>s</i></span>, and <span class=\"tex-span\"><i>C</i></span> and <span class=\"tex-span\"><i>D</i></span> are substrings of <span class=\"tex-span\"><i>t</i></span>.</p><p><img alt=\" \" src=\"https://assets.codeforces.com/images/162/CF162D1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>It is possible to reach the goal state from the start state if there exists an instruction <span class=\"tex-span\"><i>I</i></span> such that:</p> <ul> <li>1 <span class=\"tex-span\"><i>A</i></span> is a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>2 <span class=\"tex-span\"><i>B</i></span> is not a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>3 <span class=\"tex-span\"><i>C</i></span> is a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> <li>4 <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>I</i></span>.</li> </ul><p>So we want to check if such string <span class=\"tex-span\"><i>I</i></span> exists. (string <span class=\"tex-span\"><i>s</i>1</span> is called a subsequence of <span class=\"tex-span\"><i>s</i>2</span> if it is possible to get <span class=\"tex-span\"><i>s</i>2</span> by removing some characters of <span class=\"tex-span\"><i>s</i>1</span>)</p><p>There are some obvious "NO" cases. When <span class=\"tex-span\"><i>D</i></span> is a subsequence of <span class=\"tex-span\"><i>A</i></span>, it is impossible to satisfy both conditions 1 and 4. Similarly, <span class=\"tex-span\"><i>B</i></span> must not be a subsequence of <span class=\"tex-span\"><i>C</i></span>. Are these sufficient conditions? Let's try to prove this hypothesis.</p><p>To simplify the description we will introduce some new variables. Let <span class=\"tex-span\"><i>A</i>'</span>, <span class=\"tex-span\"><i>B</i>'</span>, <span class=\"tex-span\"><i>C</i>'</span>, and <span class=\"tex-span\"><i>D</i>'</span> be strings that can be obtained by removing the first characters of <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span>, <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>D</i></span>. Let <span class=\"tex-span\"><i>c</i>1</span> and <span class=\"tex-span\"><i>c</i>2</span> be the first characters of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span>.</p><p><img alt=\" \" src=\"https://assets.codeforces.com/images/162/CF162D2.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Suppose that currently the conditions are satisfied (i.e. <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> is not a subsequence of <span class=\"tex-span\"><i>C</i></span>).</p> <ul> <li>If <span class=\"tex-span\"><i>c</i>1 = <i>c</i>2</span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>1 = <i>c</i>2</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>', <i>B</i>', <i>C</i>', <i>D</i>')</span> and this also satisies the conditions.</li> <li>If <span class=\"tex-span\"><i>c</i>1 ≠ <i>c</i>2</span> and <span class=\"tex-span\"><i>B</i>'</span> is not a subsequnce of <span class=\"tex-span\"><i>C</i></span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>1</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>', <i>B</i>', <i>C</i>, <i>D</i>)</span> and this also satisies the conditions.</li> <li>If <span class=\"tex-span\"><i>c</i>1 ≠ <i>c</i>2</span> and <span class=\"tex-span\"><i>D</i>'</span> is not a subsequnce of <span class=\"tex-span\"><i>A</i></span>, you should perform the instruction <span class=\"tex-span\"><i>c</i>2</span>. The new quatruplet will be <span class=\"tex-span\">(<i>A</i>, <i>B</i>, <i>C</i>', <i>D</i>')</span> and this also satisies the conditions.</li> </ul><p>What happens if all of the above three conditions don't hold? In this case <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span> have the same length and <span class=\"tex-span\"><i>A</i> = <i>c</i>1<i>c</i>2<i>c</i>1<i>c</i>2...</span>, <span class=\"tex-span\"><i>B</i> = <i>c</i>2<i>c</i>1<i>c</i>2<i>c</i>1</span>. In particular the last two characters of <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are swapped: there are different characters <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> and <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span>, <span class=\"tex-span\"><i>B</i> = ...<i>yx</i></span>. Now you found a new necessary condition! Generally, if <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> are of the form <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span> and <span class=\"tex-span\"><i>B</i> = ...<i>yx</i></span>, the goal state is unreachable. If the last instruction is <span class=\"tex-span\"><i>x</i></span>, Vasya must be in the goal before the last instruction, but then Vasya will go further after the last instruction. If the last instruction is <span class=\"tex-span\"><i>y</i></span>, we will also get a contradiction.</p><p>Finally we have a solution. The goal state is reachable from the start state if and only if <span class=\"tex-span\"><i>D</i></span> is not a subsequence of <span class=\"tex-span\"><i>A</i></span>, <span class=\"tex-span\"><i>B</i></span> is not a subsequnce of <span class=\"tex-span\"><i>C</i></span>, and <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>C</i></span> are not of the form <span class=\"tex-span\"><i>A</i> = ...<i>xy</i></span>, <span class=\"tex-span\"><i>C</i> = ...<i>yx</i></span>. The remaining part is relatively easy, so I'll leave it as an exercise for readers. </p><h4><a href=\"//codeforces.com/problemset/problem/264/E\">Div1 E Roadside Trees</a> (Author: <a class=\"rated-user user-blue\" href=\"/profile/snuke\" title=\"Expert snuke\">snuke</a>)</h4><p>For this problem there are slides: Please check <a href=\"https://speakerdeck.com/snuke/codeforces162-div1-e\">here</a>.</p><p>UPD: Thank you for pointing out mistakes. They are fixed.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/265\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 162 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/264\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 162 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-293-6525\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"293\",\n blogEntryId: \"6478\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6525\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+54</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6525\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/rng_58\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/rng_58\">\n rng_58\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/21/2013 18:21\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6478#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6478#comments\">\n 67\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6535\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (52)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119220\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zuev93\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/34580/avatar/db7a610a3504172f.jpg'/> </a>\n <div><a href=\"/profile/zuev93\" title=\"Specialist zuev93\" class=\"rated-user user-cyan\">zuev93</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119220\" href=\"?#comment-119220\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119220\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119220\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"34580\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119220\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's nice to know that you idea for hard problem (Div 1 C) (for me certainly) is absolutely right=) But not enough time for debugging and AC=(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119220 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119220 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119220\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119221\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:02\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119221\" href=\"?#comment-119221\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119221\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119221\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have solved the div1 A problem using the mentioned algorithm, but I still receive that TLE error on the 31st test. I use Ruby. Is there a Ruby solution, which will pass the time test?</p><p>Here is my algorithm:</p> <pre><code>q = gets.chomp\nleft = []\nright = []\ni = 0\nq.each_char do |char|\n i += 1\n ((char == 'l') ? right : left) << i\nend\nputs left\nputs right.reverse\n</code></pre><p>Thanks in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119221 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119221 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119221\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119225\" commentParentId=\"119221\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2013 19:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119225\" href=\"?#comment-119225\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119221\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119225\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119225\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ruby is slow. Use C++, FPC, Java, C# and it will be accepted.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119225 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119225 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119225\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119752\" commentParentId=\"119225\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Alireza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1843/avatar/6e649a6dce114e29.jpg'/> </a>\n <div><a href=\"/profile/Alireza\" title=\"Expert Alireza\" class=\"rated-user user-blue\">Alireza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 20:25\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119752\" href=\"?#comment-119752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119225\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1843\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My C++ Solution got also TLE. I used vectors and Microsoft Visual C++ Compiler! But using Gnu C++, It got Accepted!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119338\" commentParentId=\"119221\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/safeasmilk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4507/avatar/16117820f2dabe57.jpg'/> </a>\n <div><a href=\"/profile/safeasmilk\" title=\"Expert safeasmilk\" class=\"rated-user user-blue\">safeasmilk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 00:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119338\" href=\"?#comment-119338\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119221\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119338\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"15\"\r\n data-commentUserId=\"4507\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+15</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119338\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A citation from <a href=\"//codeforces.com/blog/entry/79\">here</a>:</p> <blockquote><p>It is not guaranteed that all the problems will have solutions in all the given languages (it's especially about the scripting ones).</p> </blockquote><p>Some folks managed to pass with Python, but it may happen that in Ruby I/O functions are much too slow to get AC.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119338 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119338 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119338\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119343\" commentParentId=\"119338\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 00:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119343\" href=\"?#comment-119343\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119338\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119343\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119343\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thank you. Tommorow there will be a match, and now I'm deciding which language to use. I have looked through all the submissions to that tasks, way most of them are written with C++, some Java, and even two Python solutions. Nothing else. My "second favourite" language is C#, and I have written a solution to the same problem in C#, but... <code>Превышено ограничение времени на тесте 35</code> (TLE on 35th). So, C# is too slow too? Here is my C# code</p> <pre><code>using System;\nusing System.Collections.Generic;\nusing System.Linq;\nusing System.Text;\n\nnamespace ConsoleApplication\n{\n class Program\n {\n public static void Main(string[] args)\n {\n var s = Console.ReadLine();\n var l = new List<int>();\n var r = new List<int>();\n var i = 0;\n foreach (char c in s)\n {\n i++;\n if(c=='l')\n {\n r.Add(i);\n }\n else\n {\n l.Add(i);\n }\n }\n foreach (int i12 in l)\n {\n Console.WriteLine(i12);\n }\n r.Reverse();\n foreach (int i2 in r)\n {\n Console.WriteLine(i2);\n }\n }\n }\n}\n\n</code></pre><p>In one of Java solutions I've seen class "FastScanner" with only method "FastRead", which reads from STDIO. If you think that the time issue is in IO, maybe there is a possibility to write some wrappers aroung Ruby's gets and puts? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119343 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119343 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119343\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119360\" commentParentId=\"119343\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119360\" href=\"?#comment-119360\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119343\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119360\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119360\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't now C# well but I think <code>WriteLine</code> method flushes the output. I inserted a hack into your solution and it passed: <a href=\"/contest/264/submission/2981286\" title=\"Submission 2981286 by dalex\">2981286</a></p><p>But it's better to write your own input/output class. I know user <a class=\"rated-user user-orange\" href=\"/profile/it4.kp\" title=\"Master it4.kp\">it4.kp</a> uses C# — look over his submissions.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119360 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119360 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119360\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119368\" commentParentId=\"119360\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roman.brodetski\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/roman.brodetski\" title=\"Expert roman.brodetski\" class=\"rated-user user-blue\">roman.brodetski</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119368\" href=\"?#comment-119368\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119360\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119368\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"83724\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119368\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Wow, your advice is EXTREMELY useful! Thank you.</p><p>I have tried same in Ruby, and now it fails on 45th, not 31st test. I just replaced that <code>puts left</code> with puts <code>left.join("\\n")</code>, and the perfomance went up dramaticly. So, it seems that the weakest part in Ruby is the IO. Will think about it more.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119368 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119368 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119368\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119370\" commentParentId=\"119343\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guliash\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53487/avatar/6a2a47f3d347fce7.jpg'/> </a>\n <div><a href=\"/profile/Guliash\" title=\"Pupil Guliash\" class=\"rated-user user-green\">Guliash</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:35\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119370\" href=\"?#comment-119370\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119343\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119370\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119370\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53487\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119370\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello. Just use StringBuilder. But don't forget that it uses a lot of memory. Example:<a href=\"https://codeforces.com/contest/265/submission/2974651\">http://codeforces.com/contest/265/submission/2974651</a> Also you can use a small buffer: <a href=\"https://codeforces.com/contest/265/submission/2974575\">http://codeforces.com/contest/265/submission/2974575</a> That is <a class=\"rated-user user-orange\" href=\"/profile/eduardische\" title=\"Master eduardische\">eduardische</a>'s advice. And.. Console.Write() works faster than Console.WriteLine(). <a href=\"https://codeforces.com/contest/265/submission/2973339\">http://codeforces.com/contest/265/submission/2973339</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119370 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119370 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119370\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119371\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:43\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119371\" href=\"?#comment-119371\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119371\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119371\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can't view images from the problem Div1 D: 403 forbitten. :-(</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119371 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119371 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119371\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119374\" commentParentId=\"119371\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/rng_58\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/733/avatar/12337379adfa9a4c.jpg'/> </a>\n <div><a href=\"/profile/rng_58\" title=\"Legendary Grandmaster rng_58\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">r</span>ng_58</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 01:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119374\" href=\"?#comment-119374\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119371\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119374\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119374\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Fixed now.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119374 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119374 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119374\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121846\" commentParentId=\"119374\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/11/2013 15:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121846\" href=\"?#comment-121846\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119374\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121846\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121846\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems in problem D should be "A = c1c2c1c2..., C = c2c1c2c1." instead of "A = c1c2c1c2..., B = c2c1c2c1." And further should be C instead of B.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121846 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121846 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121846\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119379\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jill-jenn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/61244/avatar/379a15a12e1d32c7.jpg'/> </a>\n <div><a href=\"/profile/jill-jenn\" title=\"Expert jill-jenn\" class=\"rated-user user-blue\">jill-jenn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 02:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119379\" href=\"?#comment-119379\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119379\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119379\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"61244\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119379\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I assume you meant “when <em>i</em> is a <em>divisor</em> of <em>x</em>” instead of “when <em>i</em> is a <em>multiple</em> of <em>x</em>.”, in Good Sequences.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119379 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119379 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119379\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119385\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hupmscy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/26636/avatar/20574dd78ad48c95.jpg'/> </a>\n <div><a href=\"/profile/hupmscy\" title=\"Specialist hupmscy\" class=\"rated-user user-cyan\">hupmscy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:03\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119385\" href=\"?#comment-119385\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119385\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"26636\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119385\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div2 D Good Sequences, I don't understand why the sum of the number of the diviser from 1 to n is O(nlogn). Can someone prove it? </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119385 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119385 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119385\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119391\" commentParentId=\"119385\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/nishant4\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/nishant4\" title=\"Candidate Master nishant4\" class=\"rated-user user-violet\">nishant4</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:24\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119391\" href=\"?#comment-119391\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119385\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119391\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"57571\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119391\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Let p be a number in the range 1 — n Now, p will divide n/p no.s Sum of no. of divisors — {Summation(p = 1 to n)} n/p <= n * {Summation(p = 1 to n)} 1/p = n * H(n) ( H is sum of harmonic series ) and since ln(n) < H(n) < ln(n) + 1 thus, n * ln(n) < Answer < n * (ln(n) + 1)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119391 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119391 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119391\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119388\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Martuza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12501/avatar/b25fe2e78d5c1ec.jpg'/> </a>\n <div><a href=\"/profile/Martuza\" title=\"Pupil Martuza\" class=\"rated-user user-green\">Martuza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/22/2013 10:23\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119388\" href=\"?#comment-119388\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119388\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119388\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"12501\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119388\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 A / Div2 C Escape from Stones (Author: DEGwer) :</p><p>My solution is in O(2n), But code is so simple like it,</p> <pre><code>int main(){\n\tstring a;\n\tcin>>a;\n\tfor(long i=0; i<a.size(); i++)\n\tif(a[i]=='r') cout<<i+1<<endl;\n\t\t\n\tfor(long i=a.size()-1; i>=0; i--)\n\tif(a[i]=='l') cout<<i+1<<endl;\n\t\n return 0;\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119388 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119388 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119388\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"136294\" commentParentId=\"119388\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/moji\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/80646/avatar/7b6fe780caa2c87c.jpg'/> </a>\n <div><a href=\"/profile/moji\" title=\"Candidate Master moji\" class=\"rated-user user-violet\">moji</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2013 10:35\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-136294\" href=\"?#comment-136294\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119388\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"136294\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"136294\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"80646\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-136294\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>nice! But actually O(2n) = O(n) by the definition.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-136294 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-136294 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-136294\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120163\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Calvinxiao\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Calvinxiao\" title=\"Expert Calvinxiao\" class=\"rated-user user-blue\">Calvinxiao</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 09:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120163\" href=\"?#comment-120163\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120163\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"54647\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120163\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div1 A/Div2 C</p><p><code>Finally, you should print the integers in the first vector by default order, after that, you should print the integers in the second vector in the reverse order.</code></p><p>should be: Finally, you should print the integers in the <strong>second</strong> vector by default order, after that, you should print the integers in the <strong>first</strong> vector in the reverse order.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120163 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120163 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120163\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Prestige\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/19197/avatar/cf8ba2c2433b97.jpg'/> </a>\n <div><a href=\"/profile/Prestige\" title=\"Pupil Prestige\" class=\"rated-user user-green\">Prestige</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 14:30\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120170\" href=\"?#comment-120170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120170\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-11\"\r\n data-commentUserId=\"19197\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>2 problems of 7 are made by round author)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"214721\" commentParentId=\"120170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/catlak_profesor_mfb\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/128467/avatar/81a7af0e3b8fb3f0.jpg'/> </a>\n <div><a href=\"/profile/catlak_profesor_mfb\" title=\"Candidate Master catlak_profesor_mfb\" class=\"rated-user user-violet\">catlak_profesor_mfb</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/25/2015 01:23\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-214721\" href=\"?#comment-214721\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"214721\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"128467\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-214721\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>So what?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-214721 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-214721 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-214721\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"244903\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/OmaeWaMouShenDeiru\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/88303/avatar/2756cc1cc5d9a15c.jpg'/> </a>\n <div><a href=\"/profile/OmaeWaMouShenDeiru\" title=\"Pupil OmaeWaMouShenDeiru\" class=\"rated-user user-green\">OmaeWaMouShenDeiru</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/10/2015 12:31\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-244903\" href=\"?#comment-244903\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"244903\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"88303\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-244903\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved DIV 2 C by looking at the input and output, I never understood the problem statement !! </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-244903 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-244903 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-244903\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"251734\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ananth94\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/211746/avatar/72fbf14db6a1bcdc.jpg'/> </a>\n <div><a href=\"/profile/ananth94\" title=\"Specialist ananth94\" class=\"rated-user user-cyan\">ananth94</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/19/2015 21:38\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-251734\" href=\"?#comment-251734\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"251734\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"211746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-251734\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could someone explain DIV1-C in more detail? Thanks.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-251734 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-251734 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-251734\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"286092\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/divyank1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/143482/avatar/3da31c0aab0a7196.jpg'/> </a>\n <div><a href=\"/profile/divyank1\" title=\"Specialist divyank1\" class=\"rated-user user-cyan\">divyank1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/26/2016 16:46\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-286092\" href=\"?#comment-286092\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"286092\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"143482\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-286092\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Div2 C <em>Escape from Stones</em> can also be solved using <em>Doubly Linked Lists</em>.</p><p>Maintain a pointer <code>operatingPointer</code> which is initialized to the <code>head</code> of list (head of the list contains 1).</p><p>if we encounter 'l' at <code>ith</code> position of input add i+1 to the <code>left</code> of <code>operatingPointer</code> and update <code>operatingPointer</code> to newly created node.</p><p>Similarly if we encounter 'r' at <code>ith</code> position of the string add i+1 to the <code>right</code> of <code>operatingPointer</code> and update <code>operatingPointer</code> to newly created node.</p><p>Then print the whole list.</p><p><a href=\"//codeforces.com/contest/264/submission/16956916\">Implementation using Doubly Linked Lists</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-286092 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-286092 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-286092\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"296233\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/szawinis\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/413991/avatar/77a65dc71d2f7f59.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/szawinis\" title=\"Candidate Master szawinis\" class=\"rated-user user-violet\">szawinis</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/28/2016 05:41\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-296233\" href=\"?#comment-296233\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"296233\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"413991\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-296233\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Div 2 D/ Div 1 B, why do we have to update d[i] for all divisors of x? Can someone explain? Thanks in advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-296233 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-296233 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-296233\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"640442\" commentParentId=\"296233\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/AbhishekAg\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/AbhishekAg\" title=\"Expert AbhishekAg\" class=\"rated-user user-blue\">AbhishekAg</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2020 13:23\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-640442\" href=\"?#comment-640442\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-296233\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"640442\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"826040\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-640442\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Getting wrong answer for test 13 in div1 b......Can someone explain what is wrong in <a href=\"https://codeforces.com/problemset/submission/264/83518635\">this</a>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-640442 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-640442 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-640442\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"301587\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/HalfBloodPrince\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/332453/avatar/a1a516d280a7dbef.jpg'/> </a>\n <div><a href=\"/profile/HalfBloodPrince\" title=\"Expert HalfBloodPrince\" class=\"rated-user user-blue\">HalfBloodPrince</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/21/2016 18:23\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-301587\" href=\"?#comment-301587\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"301587\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"301587\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"332453\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-301587\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could a top-down approach be used for div1 B/div2 D? I tried a top down approach but I am not able to memoize it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-301587 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-301587 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-301587\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"310750\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/red_dust\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/417513/avatar/d7a2f654b2949853.jpg'/> </a>\n <div><a href=\"/profile/red_dust\" title=\"Expert red_dust\" class=\"rated-user user-blue\">red_dust</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/19/2016 11:02\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-310750\" href=\"?#comment-310750\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"310750\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"417513\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-310750\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In Div A/Div2 C Escape from Stones the algorithm is easy to understand if someone explains it,</p><p>but I don't understand how this solution came to be, which trail of thought led to this solution.</p><p>can someone please explain it.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-310750 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-310750 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-310750\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"331390\" commentParentId=\"310750\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marlonbymendes\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/358576/avatar/a4da054df60816b9.jpg'/> </a>\n <div><a href=\"/profile/marlonbymendes\" title=\"Expert marlonbymendes\" class=\"rated-user user-blue\">marlonbymendes</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/18/2016 00:15\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-331390\" href=\"?#comment-331390\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-310750\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"331390\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"358576\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-331390\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Read my comment below.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-331390 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-331390 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-331390\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"331388\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/marlonbymendes\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/358576/avatar/a4da054df60816b9.jpg'/> </a>\n <div><a href=\"/profile/marlonbymendes\" title=\"Expert marlonbymendes\" class=\"rated-user user-blue\">marlonbymendes</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/18/2016 00:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-331388\" href=\"?#comment-331388\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"331388\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"358576\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-331388\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think editorial nor comments explanation on solution <a href=\"/contest/264/problem/A\" title=\"Codeforces Round 162 (Div. 1)\">264A - Escape from Stones</a> are intuitive so I'll try to explain how I came up with a solution. </p><p>You can visualize the problem as a binary tree. Each node is responsable for a interval <strong>[a, b]</strong>. Starting from the root, responsable for <strong>[0, 1]</strong>, if you go left then root will have a left child responsable for interval <strong>[0, 1 / 2]</strong>. Since you're a left child, last time the stone fell on position 1 / 2, the end point of the interval.</p><p>Note that from that child, it doesn't matter if you go left or right: the stone will never fall on a position bigger than 1 / 2 (the end point). The ideia is: since a stone always fall on the midpoint <strong>(a + b) / 2</strong> of the lower and end points, it can never fall after the endpoint. In fact, the stone must fall infinitely many times to the right to reach that endpoint. So, we were on a node [0, 1], the stone fell and we jumped to the left, creating a left child [0, 1 / 2] and we now know that there is no way the stone will every fall to a position > 1 / 2. This means that in the final solution, the current node [0, 1 / 2] will come AFTER all nodes (descendents) that come after this one.</p><p>If we jumped to the right instead, creating a right child responsable for interval [1 / 2, 1] we can show the same way that the stone will never fall before the starting point 1 / 2. This means that the current node will com BEFORE all nodes (descendents) that come after this one, since we know that the stone can't fall on a postion < 1 / 2 from now on.</p><p>This is an algorithm: if in the i'th stone we jumped to the left, we now that stone i will become AFTER all next stones. If we jumped right, stone i will become BEFORE all next stones.</p><p>Code: <a href=\"/contest/264/submission/23071895\" title=\"Submission 23071895 by marlonbymendes\">23071895</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-331388 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-331388 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-331388\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"386173\" commentParentId=\"331388\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ameyanator\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/464121/avatar/e34f7dc2b59a7b4c.jpg'/> </a>\n <div><a href=\"/profile/ameyanator\" title=\"Specialist ameyanator\" class=\"rated-user user-cyan\">ameyanator</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/18/2017 10:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-386173\" href=\"?#comment-386173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-331388\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"386173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"464121\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-386173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Awesome explanation thanks! :')</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-386173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-386173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-386173\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360590\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/the_an0nym0us\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/303591/avatar/41fc9495b1ea2f27.jpg'/> </a>\n <div><a href=\"/profile/the_an0nym0us\" title=\"Specialist the_an0nym0us\" class=\"rated-user user-cyan\">the_an0nym0us</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/17/2017 08:56\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360590\" href=\"?#comment-360590\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"360590\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"303591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360590\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Strange! My C++ code got accepted with printf but got TLE with cout. This is too harsh</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360590 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360590 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360590\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"360690\" commentParentId=\"360590\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Guy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/559880/avatar/fd0565aa541e0d1.jpg'/> </a>\n <div><a href=\"/profile/Guy\" title=\"Candidate Master Guy\" class=\"rated-user user-violet\">Guy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/18/2017 10:00\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-360690\" href=\"?#comment-360690\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-360590\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"360690\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"360690\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"559880\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-360690\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>printf is faster than cout. if u want to use cout its better type ios::sync_with_stdio(false),cin.tie(0),cout.tie(0); in your code this make cout fast</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-360690 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-360690 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-360690\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"365999\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akhi29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207626/avatar/c39a3ca998f53094.jpg'/> </a>\n <div><a href=\"/profile/akhi29\" title=\"Pupil akhi29\" class=\"rated-user user-green\">akhi29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2017 01:33\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-365999\" href=\"?#comment-365999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"365999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"365999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207626\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-365999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm unable to solve Escape from Stones in java. In spite of using fast io, it always gives me a TLE now matter how much i optimize it <a href=\"//codeforces.com/contest/264/submission/27712057\">sol</a> did anyone get it AC in java?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-365999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-365999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-365999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"385333\" commentParentId=\"365999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zodiacleo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/zodiacleo\" title=\"Pupil zodiacleo\" class=\"rated-user user-green\">zodiacleo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2017 11:29\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-385333\" href=\"?#comment-385333\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-365999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"385333\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"145879\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-385333\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hi <a class=\"rated-user user-green\" href=\"/profile/akhi29\" title=\"Pupil akhi29\">akhi29</a><br />Two points-<br />1. Try to use <code>StringBuilder</code> (popular practice among Java user's) instead of directly printing to the output console.<br />2. When you call, <code>close()</code> of <code>PrintStream</code>, it isn't obliged to flush your output to the console. You need to call <code>flush()</code> explicitly to ensure that the data, if present in the buffer is flushed to the output console. You can refer the modified submission <a href=\"/contest/264/submission/30322735\" title=\"Submission 30322735 by zodiacleo\">30322735</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-385333 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-385333 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-385333\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"587566\" commentParentId=\"385333\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/akhi29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/207626/avatar/c39a3ca998f53094.jpg'/> </a>\n <div><a href=\"/profile/akhi29\" title=\"Pupil akhi29\" class=\"rated-user user-green\">akhi29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/11/2020 01:45\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-587566\" href=\"?#comment-587566\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-385333\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"587566\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"207626\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-587566\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks zodiacleo</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-587566 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-587566 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-587566\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"379370\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Target2018\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/295556/avatar/f6fe0b640b7fee7.jpg'/> </a>\n <div><a href=\"/profile/Target2018\" title=\"Newbie Target2018\" class=\"rated-user user-gray\">Target2018</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/18/2017 18:55\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-379370\" href=\"?#comment-379370\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"379370\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"295556\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-379370\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In <a href=\"//codeforces.com/contest/265/problem/C\">DIV 2 C</a> I took 2 variables hi = 1 and lo = 0, if character is 'l' then I just change hi = (hi + lo) / 2 otherwise lo = (hi + lo) / 2 and mapped the value, sort them and print them, but got WA on Testcase 11, could you please tell me what is I'm missing?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-379370 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-379370 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-379370\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"384618\" commentParentId=\"379370\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bibhuti\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/561745/avatar/eb1f97e82517cf9e.jpg'/> </a>\n <div><a href=\"/profile/Bibhuti\" title=\"Specialist Bibhuti\" class=\"rated-user user-cyan\">Bibhuti</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/07/2017 19:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-384618\" href=\"?#comment-384618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-379370\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"384618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"561745\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-384618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I hope it may be because of the precision problem. I am also facing the same and below is my solution</p><p><a href=\"/contest/264/submission/30185936\" title=\"Submission 30185936 by Bibhuti\">30185936</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-384618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-384618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-384618\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"396488\" commentParentId=\"384618\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/neroond\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/375945/avatar/2a26526cf4420757.jpg'/> </a>\n <div><a href=\"/profile/neroond\" title=\"Expert neroond\" class=\"rated-user user-blue\">neroond</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/21/2017 13:26\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-396488\" href=\"?#comment-396488\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-384618\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"396488\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"375945\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-396488\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>in DIV2 D what will be answer in case 5 : 2 4 8 6 9. My solution that got AC. outputs 5, but how? 8 is bigger than 6 they can't form a sequence </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-396488 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-396488 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-396488\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"411637\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/sabertooth\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/547698/avatar/2106fe4acab8cfe4.jpg'/> </a>\n <div><a href=\"/profile/sabertooth\" title=\"Specialist sabertooth\" class=\"rated-user user-cyan\">sabertooth</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/02/2018 07:14\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-411637\" href=\"?#comment-411637\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"411637\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"411637\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"547698\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-411637\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In <strong>Div 1 A</strong> Stones falls in 'k' position and print the stone position from left</p><p>I calculated 'k' and 'd' as k=(X+Y)/2 and d=(Y-X)/2 And if 'l' then x-=d otherwise y+=d. then sorted the array which contains 'k' s value and its position no. but my implementation isn't matching with the test case..</p><p>Did I misunderstood the ques or my idea is wrong?</p><p><a href=\"https://paste.ubuntu.com/26503881/\">CODE</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-411637 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-411637 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-411637\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"453240\" commentParentId=\"411637\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wallcrawler\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/446649/avatar/28b029f94566d9b0.jpg'/> </a>\n <div><a href=\"/profile/wallcrawler\" title=\"Expert wallcrawler\" class=\"rated-user user-blue\">wallcrawler</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/22/2018 10:35\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-453240\" href=\"?#comment-453240\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-411637\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"453240\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"446649\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-453240\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The thing is that, suppose you only go left then it means that the stones would be at 1/2,1/4,1/8,...till 1/(2^(10^6)) (considering maximum length of the string) which can't be stored in the float value.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-453240 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-453240 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-453240\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"469926\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/umangahuja1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/480801/avatar/6a0f8d27102d0ec0.jpg'/> </a>\n <div><a href=\"/profile/umangahuja1\" title=\"Expert umangahuja1\" class=\"rated-user user-blue\">umangahuja1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Nov/09/2018 11:09\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-469926\" href=\"?#comment-469926\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"469926\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"480801\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-469926\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For those facing TLE in the problem Div1 A (Div2 C Escape from Stones) in C++ even with <code>O(N)</code> time complexity the reason can be <code>endl vs '\\n'</code>.</p><p><code>'\\n</code>' inserts a new line to the output stream while</p><p><code>endl</code> inserts a new line as well as flushes the output stream.</p><p>So using <code>'\\n'</code>can solve the TLE issue.</p><p>Also you can use fast IO with cin/cout too instead of using scanf/printf by adding these lines in your code.</p><p><code>ios::sync_with_stdio(false);</code></p><p><code>cin.tie(0);</code></p><p><code>cout.tie(0);</code></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-469926 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-469926 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-469926\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"494267\" commentParentId=\"469926\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SohrabRoohi\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SohrabRoohi\" title=\"Specialist SohrabRoohi\" class=\"rated-user user-cyan\">SohrabRoohi</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/22/2019 01:54\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-494267\" href=\"?#comment-494267\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-469926\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"494267\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"620634\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-494267\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Believe it or not this actually solved the problem for me. I was using a linked list and basically pushing to the front and back and was confused how I was getting TLE with 1,000,000 O(1) operations. I ended up writing my own code for a linked list and still failed case 31, changing the endl to \\n made it accepted. This made it go from 2000 ms TLE to 233 ms, thank you for your post.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-494267 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-494267 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-494267\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512701\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pseudocoder10\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/pseudocoder10\" title=\"Master pseudocoder10\" class=\"rated-user user-orange\">pseudocoder10</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2019 15:13\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512701\" href=\"?#comment-512701\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"512701\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"512701\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"786409\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512701\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I solved div1A using a binary tree, if character is l then i add to the left of parent node otherwise i add to the right, then an inorder traversal will give the answer but im getting TLE at testcase 31 idk why since my code is implemented in O(n) complexity. My solution(<a href=\"https://codeforces.com/contest/264/submission/54413614\">https://codeforces.com/contest/264/submission/54413614</a>)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512701 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512701 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512701\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"553043\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wolfie.\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/889894/avatar/b1389c1ceb58933b.jpg'/> </a>\n <div><a href=\"/profile/wolfie.\" title=\"Expert wolfie.\" class=\"rated-user user-blue\">wolfie.</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2019 17:58\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-553043\" href=\"?#comment-553043\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"553043\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"553043\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"889894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-553043\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Something is wrong with the testing of the question Div 1(A)/ Div2(C) . Got 2 TLE's on a O(n) solution [Test Case 31] , changed endl and to '\\n' and then got runtime error on test 41. </p><p>TLE — <a href=\"https://codeforces.com/contest/265/submission/63245660\">https://codeforces.com/contest/265/submission/63245660</a> Runtime Error — <a href=\"https://codeforces.com/contest/265/submission/63246396\">https://codeforces.com/contest/265/submission/63246396</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-553043 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-553043 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-553043\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621308\" commentParentId=\"553043\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/UNOwen98\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/UNOwen98\" title=\"Expert UNOwen98\" class=\"rated-user user-blue\">UNOwen98</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 09:56\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621308\" href=\"?#comment-621308\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-553043\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621308\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1254135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621308\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I am facing the same problem. Were you able to fix it ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621308 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621308 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621308\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621403\" commentParentId=\"621308\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/wolfie.\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/889894/avatar/b1389c1ceb58933b.jpg'/> </a>\n <div><a href=\"/profile/wolfie.\" title=\"Expert wolfie.\" class=\"rated-user user-blue\">wolfie.</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 13:01\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621403\" href=\"?#comment-621403\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-621308\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621403\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"889894\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621403\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, i kept on getting runtime error with that approach.. so i changed my implementation a little bit, and it got accepted. <a href=\"https://codeforces.com/contest/265/submission/63246871\">Accepted Solution.</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621403 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621403 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621403\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"621435\" commentParentId=\"621403\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/UNOwen98\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/UNOwen98\" title=\"Expert UNOwen98\" class=\"rated-user user-blue\">UNOwen98</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/13/2020 13:39\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-621435\" href=\"?#comment-621435\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-621403\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"621435\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"1254135\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-621435\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I had to do this too. I guess the problem was caused because the second loop ( which is being run backwards ) was trying to access some invalid memory. The problems gets fixed when the array is reversed and loop is run forward.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-621435 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-621435 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-621435\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"664098\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iabhishek15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1226114/avatar/6ce33a9f7d454deb.jpg'/> </a>\n <div><a href=\"/profile/iabhishek15\" title=\"Expert iabhishek15\" class=\"rated-user user-blue\">iabhishek15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2020 19:31\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-664098\" href=\"?#comment-664098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"664098\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"664098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1226114\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-664098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have an another approach for div1B. for each number check the maxm times a divisor has occurred from all the divisors of a number and then increase the maxm by 1 and iterate again and update all the divisors</p><p>code <a href=\"/contest/264/submission/87253298\" title=\"Submission 87253298 by iabhishek15\">87253298</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-664098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-664098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-664098\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1035696\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ahmed_ElGendy56\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2725312/avatar/e34f70ed817bafea.jpg'/> </a>\n <div><a href=\"/profile/Ahmed_ElGendy56\" title=\"Pupil Ahmed_ElGendy56\" class=\"rated-user user-green\">Ahmed_ElGendy56</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/07/2023 19:42\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1035696\" href=\"?#comment-1035696\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1035696\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-7\"\r\n data-commentUserId=\"2725312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1035696\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you are using C++ for solving (Div1 A / Div2 C Escape from Stones) and got a TLE error on the 31st test you have to be sure you are using ("\\n") instead of (endl) because (endl) takes more time for flushing.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1035696 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1035696 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1035696\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046784\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/oishi_161\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2006012/avatar/8428423d6c055dae.jpg'/> </a>\n <div><a href=\"/profile/oishi_161\" title=\"Newbie oishi_161\" class=\"rated-user user-gray\">oishi_161</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 11:18\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046784\" href=\"?#comment-1046784\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046784\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2006012\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046784\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can someone please explain problem div2 B in more detail?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046784 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1046784 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1046784\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046792\" commentParentId=\"1046784\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SummerSky\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/419016/avatar/8ddf3c5c2dc6bf44.jpg'/> </a>\n <div><a href=\"/profile/SummerSky\" title=\"Expert SummerSky\" class=\"rated-user user-blue\">SummerSky</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 11:36\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046792\" href=\"?#comment-1046792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-1046784\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"419016\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Note that we can only move to the next tree, but not to the previous one. So, to eat all the nuts, we must start from the first tree and visit one by one until we reach the final one. When we are on the top of some tree-i (because we must go to the top to eat that nut), and eat the nut, then we should move to the next tree. If next tree has lower height, we have to move down to the same height and then jump (to save time). Otherwise, we can directly jump to the next tree (also to save time). </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1046792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1046792\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1046818\" commentParentId=\"1046792\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/oishi_161\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2006012/avatar/8428423d6c055dae.jpg'/> </a>\n <div><a href=\"/profile/oishi_161\" title=\"Newbie oishi_161\" class=\"rated-user user-gray\">oishi_161</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2023 12:46\">3 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1046818\" href=\"?#comment-1046818\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-1046792\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1046818\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2006012\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1046818\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks a lot for your help.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1046818 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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Stones on the Table"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Stones on the Table</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There are <span class=\"tex-span\"><i>n</i></span> stones on the table in a row, each of them can be red, green or blue. Count the minimum number of stones to take from the table so that any two neighboring stones had different colors. Stones in a row are considered neighboring if there are no other stones between them.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 50)</span> — the number of stones on the table. </p><p>The next line contains string <span class=\"tex-span\"><i>s</i></span>, which represents the colors of the stones. We'll consider the stones in the row numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Then the <span class=\"tex-span\"><i>i</i></span>-th character <span class=\"tex-span\"><i>s</i></span> equals \"<span class=\"tex-font-style-tt\">R</span>\", if the <span class=\"tex-span\"><i>i</i></span>-th stone is red, \"<span class=\"tex-font-style-tt\">G</span>\", if it's green and \"<span class=\"tex-font-style-tt\">B</span>\", if it's blue.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>RRG<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>RRRRR<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>BRBG<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"f49235aa635afc60075b6407d87140e9\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e5bd61caad7ef105f73513b491ec03004e7de55a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/266\">Codeforces Round 163 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/266/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='f49235aa635afc60075b6407d87140e9'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2549\"/>\r\n 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class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6494\" title=\"Codeforces Round #163 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1457:1458\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6499\" title=\"Codeforces Round #163 (Div. 2) Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1693:1694\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/266\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/266/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/266/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/266/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/266/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/266/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/266/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/266/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_794399e220e0131747b933f2d8a806f10a556509\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Stones on the Table</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There are <span class=\"tex-span\"><i>n</i></span> stones on the table in a row, each of them can be red, green or blue. Count the minimum number of stones to take from the table so that any two neighboring stones had different colors. Stones in a row are considered neighboring if there are no other stones between them.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 50)</span> — the number of stones on the table. </p><p>The next line contains string <span class=\"tex-span\"><i>s</i></span>, which represents the colors of the stones. We'll consider the stones in the row numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Then the <span class=\"tex-span\"><i>i</i></span>-th character <span class=\"tex-span\"><i>s</i></span> equals "<span class=\"tex-font-style-tt\">R</span>", if the <span class=\"tex-span\"><i>i</i></span>-th stone is red, "<span class=\"tex-font-style-tt\">G</span>", if it's green and "<span class=\"tex-font-style-tt\">B</span>", if it's blue.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />RRG<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />RRRRR<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />BRBG<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='6a738ad05acb379636bd06c9a5923677'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6546\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6499\"> <p>Codeforces Round #163 (Div. 2) Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/266/problem/A\" title=\"Codeforces Round 163 (Div. 2)\">266A - Stones on the Table</a></p><p>In this problem you should count number of consecutive pairs of equal letters. It can be done using one cycle and <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> time.</p><p><a href=\"/contest/266/problem/B\" title=\"Codeforces Round 163 (Div. 2)\">266B - Queue at the School</a></p><p>In this you should realize the given process. You should <span class=\"tex-span\"><i>t</i></span> times swap elements <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i> + 1</span> if on the place <span class=\"tex-span\"><i>i</i></span> was a girl and on the place <span class=\"tex-span\"><i>i</i> + 1</span> was a boy. You should not push some girl to the left multiple times at once. The solution can be written using <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>T</i>)</span> time. </p><p><a href=\"/contest/266/problem/C\" title=\"Codeforces Round 163 (Div. 2)\">266C - Below the Diagonal</a></p><p>This problem can be solved using constructive algorithm. We will use inductive approach. At first, we have matrix of size <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>n</i> - 1</span> ones in it. Therefore, there is a column with no ones in it. So, we put this column to <span class=\"tex-span\"><i>n</i></span>-th place. In this case, the lower right element will be <span class=\"tex-span\">0</span>. Then find any row with at least one integer one and put it to the <span class=\"tex-span\"><i>n</i></span>-th place.</p><p>After these operations the element in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span> equals to <span class=\"tex-span\">0</span> and the last row has at least one integer one. Therefore, we can reduce the dimension of our problem, that is <span class=\"tex-span\"><i>n</i>: = <i>n</i> - 1</span>. In our new problem we have no more than <span class=\"tex-span\"><i>n</i> - 2</span> ones. So, we can solve this problem using the same algorithm. When <span class=\"tex-span\"><i>n</i></span> equals to <span class=\"tex-span\">1</span> you should finish algorithm, because there is no ones left. This algorithm uses <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> swap operations, no more than two for every <span class=\"tex-span\"><i>n</i></span>.</p><p><a href=\"/contest/266/problem/D\" title=\"Codeforces Round 163 (Div. 2)\">266D - BerDonalds</a></p><p>I'll tell a few ideas how to solve this problem. Firstly, describe the solution with time <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span>. Consider every edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> of length <span class=\"tex-span\"><i>len</i></span> where could be the answer point. Let this point lie at a distance <span class=\"tex-span\"><i>x</i></span> from vertex <span class=\"tex-span\"><i>u</i></span>. So, the distance from this point to vertex <span class=\"tex-span\"><i>i</i></span> would be <span class=\"tex-span\"><i>min</i>(<i>x</i> + <i>d</i>[<i>u</i>][<i>i</i>], <i>len</i>–<i>x</i> + <i>d</i>[<i>v</i>][<i>i</i>])</span>, where <span class=\"tex-span\"><i>d</i>[<i>x</i>][<i>y</i>]</span> — distance between vertices <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. Equate these values and get the critical value <span class=\"tex-span\"><i>x</i></span> for vertex <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\"><i>x</i> = (<i>len</i> + <i>d</i>[<i>v</i>][<i>i</i>]–<i>d</i>[<i>u</i>][<i>i</i>]) / 2</span>. It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations.</p><p>Another solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>·<i>log</i><sup class=\"upper-index\">2</sup>)</span>. Multiply all weights by <span class=\"tex-span\">2</span>. Consider every edge where should be the answer and make binary search for the answer (in integers). To check some current value you should consider every vertex <span class=\"tex-span\"><i>i</i></span> and assume that the answer is achieved in this vertex. In this case, the answer point must lie on this edge <= some value <span class=\"tex-span\"><i>l</i>[<i>i</i>]</span> or >= some value <span class=\"tex-span\"><i>r</i>[<i>i</i>]</span>. This subproblem is solved using offline algorithm using sorting events and maintaining the balance.</p><p>Also, you can use ternary search on every edge of the graph. But you should divide every edge on several segments and find the answer on every segment, because the ternary search is incorrect in this problem.</p><p>The last two solutions can provide accepted, if you realize them carefully. Also note, that there is the solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>)</span> by the author <a class=\"rated-user user-orange\" href=\"/profile/RAD\" title=\"International Master RAD\">RAD</a>.</p><p><a href=\"/contest/266/problem/E\" title=\"Codeforces Round 163 (Div. 2)\">266E - More Queries to Array...</a></p><p>This problem can be solved using data structure. We would use segment tree, we will support <span class=\"tex-span\"><i>k</i></span> segment trees for every power. At every vertex we will calculate weighted sum of the appropriate power, also we will save some number that indicates the color of the whole segment, if any.</p><p>User <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> in comments to the post and user <a class=\"rated-user user-violet\" href=\"/profile/mexmans\" title=\"Candidate Master mexmans\">mexmans</a> in comments to the tutorial tell their formula to get the answer. I try to describe how to get them by yourself. Firstly, you should write what value your segment tree gives. The tree can calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a5b58e8b23c7841d1d63b86cb9dff69967de47a9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. You need to calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c643f7f8655fd5b92fece5daa272e472e6c8f830.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, you can write it also as <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6328f7eee132b5640555cc7d5315c4a3b3a21417.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then you should write the last sum for some first powers (at least three) (at piece of paper) and subtract the second sum (what you need) from the first sum (what your tree can calculate). You get an expression that describes what should be subtracted to get the answer from the value what you tree can calculate. This is just the Newton binomial without the highest power.</p><p>So, the answer for power <span class=\"tex-span\"><i>j</i></span> is expressed as the subtraction of the value of query to your segment tree and the Newton binomial, with all powers that are less than <span class=\"tex-span\"><i>j</i></span> (these values can also calculated using your segment tree). Partial sum of the powers and binomial coefficients can be precalced. The solution has the complexity <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>K</i>·<i>log</i>(<i>N</i>))</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/266\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 163 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-6546\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"6499\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=163\" class=\"tag notice\" style=\"text-decoration: none;\">163</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+21</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6499#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6499#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6556\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (44)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119720\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119720\" href=\"?#comment-119720\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119720\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119720\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for d & e?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119720 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119720 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119720\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119734\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ximera\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57168/avatar/5b9093f6cb7c97f6.jpg'/> </a>\n <div><a href=\"/profile/Ximera\" title=\"Master Ximera\" class=\"rated-user user-orange\">Ximera</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:59\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119734\" href=\"?#comment-119734\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119734\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"57168\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119734\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Bit patience my friend :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119734 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119734 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119734\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119742\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 19:27\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119742\" href=\"?#comment-119742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119742\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It has not been ready yet.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119742\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119748\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xeronix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8425/avatar/b652c95a2089a33b.jpg'/> </a>\n <div><a href=\"/profile/xeronix\" title=\"Expert xeronix\" class=\"rated-user user-blue\">xeronix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 20:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119748\" href=\"?#comment-119748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119748\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"8425\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For D i tried the following approach but somehow couldn't finish debugging it. </p> <pre><code>For all those vertices v whose eccentricity == radius of graph:\n For all the adjoining edges of v i.e. edge(v,x):\n Binary Search for the location l on the edge (v,x) which minimizes graph \n radius considering l as a vertex\n Keep track of minimum of all such graph radii\n</code></pre><p>Will it work ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119748\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119774\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119774\" href=\"?#comment-119774\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119774\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119774\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C the important part is how can you find the 0 row fast (I mean the row with all numbers 0 in it), because you do it O(N) times and naive way (O(N^2)) is not sufficient. I used some dynamic arrays and updated them after each swap. For me the difficulty was in implementation and not in the algorithm, I got it in about 5 minutes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119774 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119774 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119774\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119776\" commentParentId=\"119774\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guliashvili\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39591/avatar/37cde92b05e59c05.jpg'/> </a>\n <div><a href=\"/profile/guliashvili\" title=\"Candidate Master guliashvili\" class=\"rated-user user-violet\">guliashvili</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119776\" href=\"?#comment-119776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119774\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n = 1000 whats the problem with n^2 algo?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119776\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119787\" commentParentId=\"119776\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 23:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119787\" href=\"?#comment-119787\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119776\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119787\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119787\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>you do N^2 thing O(N) times, in total it becomes O(N^3). I mean in O(N) times you will have to find 0 row in remaining square. That's not a straightforward thing to do, for me it was harder than the part that is written in the tutorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119787 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119787 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119787\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119789\" commentParentId=\"119787\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119789\" href=\"?#comment-119789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119787\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>you have O(n) phases (O(n) swaps to make):\n each phase you search for the appropriate column //O(n)\n you perform the swap in O(n)\n</code></pre><p>the two steps are independent, so this gives O(n^2), which is feasible. you just need an array of size n counting the number of ones in each column to search for the appropriate column in O(n)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119789\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119791\" commentParentId=\"119789\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119791\" href=\"?#comment-119791\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119789\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119791\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119791\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>that's what I did actually</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119791 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119791 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119791\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119777\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119777\" href=\"?#comment-119777\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119777\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119777\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D and E ? at least some hint ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119777 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119777 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119777\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119850\" commentParentId=\"119777\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kraskevich\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41036/avatar/baa5690e761857ad.jpg'/> </a>\n <div><a href=\"/profile/kraskevich\" title=\"International Grandmaster kraskevich\" class=\"rated-user user-red\">kraskevich</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:18\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119850\" href=\"?#comment-119850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119777\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119850\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"41036\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>E: 1) Let's understand how to solve this problem if k for all queries to calculate the sum is equal to 0. It's quite easy to do it: we can just use a segment tree.</p><p>2) Let's learn to answer queries where k is greater than zero. Let's assume that we know a correct answer for a node's left child and right child. We need to merge node's children answers. To do it, we can figure out the following formula: answer for current node and power k ans[k] = ans_left[k] + ans_right[k] + sum for all 1 <= j <= k ans_right[k — j] * L ^ j * c[k][j], where ans_left and ans_right are the answers for node's children, c[k][j] is a binomial coefficient and L is the length of a segment represented by the left child of the node.</p><p>3) However, we still don't know how to process assign queries. But this is rather simple: if we precalculate prefix sums for all powers, we'll be able to find a value for a certain node in a tree in constant time even if its value has been updated.</p><p>Such solutuion works in O(N + M log N) time. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120420\" commentParentId=\"119850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 07:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120420\" href=\"?#comment-120420\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120420\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120420\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks for the hint</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120420 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120420 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120420\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119792\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kotenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44176/avatar/7983fd66b7982a73.jpg'/> </a>\n <div><a href=\"/profile/Kotenko\" title=\"Specialist Kotenko\" class=\"rated-user user-cyan\">Kotenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119792\" href=\"?#comment-119792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119792\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44176\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems that I had underestimated the C problem — very interesting idea to solve it.<br />Thanks for tutorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119792\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119793\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stifff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78162/avatar/af74a0645f71a854.jpg'/> </a>\n <div><a href=\"/profile/stifff\" title=\"Specialist stifff\" class=\"rated-user user-cyan\">stifff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119793\" href=\"?#comment-119793\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119793\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78162\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119793\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could I solve D Problem, using Hakimi algo, for searching an absolute center of Graph?</p><p>Article in Russian is here:</p><p><a href=\"http://www.uchimatchast.ru/teory/abs_center.php\">http://www.uchimatchast.ru/teory/abs_center.php</a></p><p>(algo in the bottom of the page)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119793 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119793 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119793\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119794\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/howsiwei\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/howsiwei\" title=\"Candidate Master howsiwei\" class=\"rated-user user-violet\">howsiwei</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 04:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119794\" href=\"?#comment-119794\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119794\" revisionCount=\"8\" revision=\"8\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">8</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119794\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77740\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119794\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem C there is an O(n) solution. <a href=\"/contest/266/submission/2997252\" title=\"Submission 2997252 by howsiwei\">2997252</a> (this is not my original idea, i learnt it from <a href=\"/contest/266/submission/2993213\" title=\"Submission 2993213 by tjsudys\">2993213</a> and edit the swap part to make it O(n)) The main idea is that after j steps, for all 1<k<=j, kth marked cell will lies in column 1 to k, row c+1(c=its column number) to j+1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119794 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119794 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119794\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119808\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:13\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119808\" href=\"?#comment-119808\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119808\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119808\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119808\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119808 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119808 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119808\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119809\" commentParentId=\"119808\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iensen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/iensen\" title=\"Candidate Master iensen\" class=\"rated-user user-violet\">iensen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119809\" href=\"?#comment-119809\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119808\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119809\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"504\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119809\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You are right that two swaps are needed, but by <a href=\"https://en.wikipedia.org/wiki/Big_O_notation\">definition of Big-O notation</a>, there is no difference between O(N) and O(2*N). O(N) means there is some fixed constant M such that algorithm works in time M*N for each input of any size N. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119809 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119809 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119809\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119813\" commentParentId=\"119809\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 12:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119813\" href=\"?#comment-119813\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119809\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119813\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119813\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119813\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119813 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119813 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119813\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119821\" commentParentId=\"119813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ramint\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/74825/avatar/8a16585522c3dce2.jpg'/> </a>\n <div><a href=\"/profile/ramint\" title=\"Newbie ramint\" class=\"rated-user user-gray\">ramint</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119821\" href=\"?#comment-119821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"74825\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>but it doesnt mean ,your swaps take o(2*n) ......</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119821\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119822\" commentParentId=\"119821\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119822\" href=\"?#comment-119822\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119821\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119822\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119822\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119822\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119822 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119822 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119822\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119811\" href=\"?#comment-119811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Tutorial for chinese version <a href=\"http://blog.csdn.net/haha593572013/article/details/8538216\">chick here</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119811\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119840\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 17:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119840\" href=\"?#comment-119840\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119840\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119840\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My idea for problem D is using ford-bellman, then with every edge[i], I find the furthest way from edge[i].x, from edge[i].y without pass through the edge[i] and determine the point, but I get WA. Anyone can explain, or have a wrong test case for that ? Thank you for helping, and sorry for my poor english :).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119840 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119840 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119840\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119845\" commentParentId=\"119840\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 18:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119845\" href=\"?#comment-119845\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119840\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119845\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119845\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>open your submission, you'll find the test cases below your code, and you'll find the one that gives your WA.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119845 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119845 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119845\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119848\" commentParentId=\"119845\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119848\" href=\"?#comment-119848\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119845\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119848\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119848\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know about that, but that one is too big.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119848 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119848 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119848\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119854\" commentParentId=\"119848\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119854\" href=\"?#comment-119854\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119848\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119854\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119854\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119854\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How do you determinate the point on edge? You can't use ternary search, because function on it isn't convex</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119854 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119854 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119854\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119856\" commentParentId=\"119854\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119856\" href=\"?#comment-119856\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119854\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119856\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119856\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>point = ( furthest(edge[i].x) — furthest(edge[i].y) + edge[i].w )/2; Is it right ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119856 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119856 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119856\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119861\" commentParentId=\"119856\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:43\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119861\" href=\"?#comment-119861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119856\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, it isn't. I thought so too, but <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> said me, that function on the edge is piece-wise linear. So you must disintegrate it on the segments. I'm still thinking, how to do it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120017\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:37\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120017\" href=\"?#comment-120017\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120017\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120017\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a Monotonicity when the answer(ans) is increasing , you will find more such points that satisfy the condition Max_shortest_distance <= ans,so i think you can try binary search of this problem .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120017 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120017 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120017\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120171\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 14:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120171\" href=\"?#comment-120171\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120171\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120171\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have you passed the solution? If yes, please write the idea :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120171 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120171 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120171\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120000\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21339/avatar/58866417a0c9f963.jpg'/> </a>\n <div><a href=\"/profile/irakli\" title=\"Specialist irakli\" class=\"rated-user user-cyan\">irakli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2013 22:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120000\" href=\"?#comment-120000\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120000\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"36\"\r\n data-commentUserId=\"21339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+36</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120000\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Still waiting for D and E solutions...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120000 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120000 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120000\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120016\" commentParentId=\"120000\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mosiomohsen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42052/avatar/5d107e4760b3f346.jpg'/> </a>\n <div><a href=\"/profile/mosiomohsen\" title=\"Specialist mosiomohsen\" class=\"rated-user user-cyan\">mosiomohsen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120016\" href=\"?#comment-120016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120000\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"42052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>:-w</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120016\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120042\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/vinaybajaj2610\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25881/avatar/4c912eb678ab859d.jpg'/> </a>\n <div><a href=\"/profile/vinaybajaj2610\" title=\"Expert vinaybajaj2610\" class=\"rated-user user-blue\">vinaybajaj2610</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 15:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120042\" href=\"?#comment-120042\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120042\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"25881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120042\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you also should provide the link to good code for each problem in contest with each problems explanation in tutorial. [ Best : Good and nice implementation and better complexity]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120042 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120042 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120042\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120059\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tjsumonster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82432/avatar/dfcbf8967ac2147c.jpg'/> </a>\n <div><a href=\"/profile/tjsumonster\" title=\"Expert tjsumonster\" class=\"rated-user user-blue\">tjsumonster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 16:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120059\" href=\"?#comment-120059\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120059\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"82432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120059\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for D & E pls!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120059 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120059 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120059\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120223\" commentParentId=\"120059\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tctony\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3000/avatar/c90abcf148ccb4c.jpg'/> </a>\n <div><a href=\"/profile/tctony\" title=\"Specialist tctony\" class=\"rated-user user-cyan\">tctony</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 08:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120223\" href=\"?#comment-120223\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120059\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120223\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"3000\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120223\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find editorial for D from problem C at <a href=\"http://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">here</a>.</p><p>Hope someone can do some explanation on E!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120223 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120223 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120223\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120275\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 19:03\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120275\" href=\"?#comment-120275\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120275\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120275\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks, nice explanation of problem D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120275 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120275 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120275\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121286\" commentParentId=\"120275\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 00:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121286\" href=\"?#comment-121286\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120275\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121286\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121286\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry but I don't think so: In the discussion of D we read: " It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations." I don't think that it is true for the 3-rd example. Even if not so, the proof is quite ambiguous. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121286 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121286 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121286\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120429\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120429\" href=\"?#comment-120429\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120429\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120429\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>whats that?</p><p>there are only solutions. where to read problems ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120429 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120429 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120429\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121254\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2013 17:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121254\" href=\"?#comment-121254\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121254\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121254\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121254\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121254 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121254 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121254\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"547929\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2019 20:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-547929\" href=\"?#comment-547929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"547929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-547929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great source for learning the Min. Diameter Spanning Tree but the link seems to be broken. Here's the web archive link for the pdf: <a href=\"https://web.archive.org/web/20160309101249/https://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">Link</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-547929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-547929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-547929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120230\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/husseincoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/5219/avatar/de8f1c32ce880839.jpg'/> </a>\n <div><a href=\"/profile/husseincoder\" title=\"Specialist husseincoder\" class=\"rated-user user-cyan\">husseincoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 14:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120230\" href=\"?#comment-120230\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120230\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5219\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120230\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my approach that gets WA.. but i don't know why..</p><p>First i compute the shortest distance between pairs using floyd warshal, then iterate all pairs getting the furthest node to each one of them.. then using binary search i get the optimal place on the road of those pair.. getting the min for every pair and printing it.</p><p>Can anybody tell me whats the problem of my solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120230 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120230 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120230\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"373902\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CaptainRubik_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/343348/avatar/19c785dbaef44419.jpg'/> </a>\n <div><a href=\"/profile/CaptainRubik_\" title=\"Pupil CaptainRubik_\" class=\"rated-user user-green\">CaptainRubik_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2017 05:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-373902\" href=\"?#comment-373902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"373902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"343348\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-373902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The tags for Div2B include Max flow. Can anyone elaborate on how to model this problem as a graph?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-373902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-373902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-373902\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"943288\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coder_firegun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1825864/avatar/c03899f54d682484.jpg'/> </a>\n <div><a href=\"/profile/coder_firegun\" title=\"Pupil coder_firegun\" class=\"rated-user user-green\">coder_firegun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/15/2022 11:23\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-943288\" href=\"?#comment-943288\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"943288\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1825864\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-943288\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve problem B when constraints are large using graphs as mentioned in problem tags</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-943288 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-943288 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-943288\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966578\" commentParentId=\"943288\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/diwaseharsh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/diwaseharsh\" title=\"Newbie diwaseharsh\" class=\"rated-user user-gray\">diwaseharsh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 10:24\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966578\" href=\"?#comment-966578\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-943288\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966578\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2517510\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966578\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also wanna know. but i dont know maps ...</p><p>can U share ur code??????</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966578 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966578 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966578\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1027114\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepaksolution\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/deepaksolution\" title=\"Unrated, deepaksolution\" class=\"rated-user user-black\">deepaksolution</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/03/2023 20:15\">5 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1027114\" href=\"?#comment-1027114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1027114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3184366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1027114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Solution of 266B — Queue at the School Is Here in the below link with explanation of code</strong></p><p><a href=\"https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html\">https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1027114 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1027114 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1027114\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6556\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea 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Queue at the School"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Queue at the School</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>During the break the schoolchildren, boys and girls, formed a queue of <span class=\"tex-span\"><i>n</i></span> people in the canteen. Initially the children stood in the order they entered the canteen. However, after a while the boys started feeling awkward for standing in front of the girls in the queue and they started letting the girls move forward each second. </p><p>Let's describe the process more precisely. Let's say that the positions in the queue are sequentially numbered by integers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>, at that the person in the position number <span class=\"tex-span\">1</span> is served first. Then, if at time <span class=\"tex-span\"><i>x</i></span> a boy stands on the <span class=\"tex-span\"><i>i</i></span>-th position and a girl stands on the <span class=\"tex-span\">(<i>i</i> + 1)</span>-th position, then at time <span class=\"tex-span\"><i>x</i> + 1</span> the <span class=\"tex-span\"><i>i</i></span>-th position will have a girl and the <span class=\"tex-span\">(<i>i</i> + 1)</span>-th position will have a boy. The time is given in seconds.</p><p>You've got the initial position of the children, at the initial moment of time. Determine the way the queue is going to look after <span class=\"tex-span\"><i>t</i></span> seconds.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>t</i> ≤ 50)</span>, which represent the number of children in the queue and the time after which the queue will transform into the arrangement you need to find. </p><p>The next line contains string <span class=\"tex-span\"><i>s</i></span>, which represents the schoolchildren's initial arrangement. If the <span class=\"tex-span\"><i>i</i></span>-th position in the queue contains a boy, then the <span class=\"tex-span\"><i>i</i></span>-th character of string <span class=\"tex-span\"><i>s</i></span> equals \"<span class=\"tex-font-style-tt\">B</span>\", otherwise the <span class=\"tex-span\"><i>i</i></span>-th character equals \"<span class=\"tex-font-style-tt\">G</span>\".</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print string <span class=\"tex-span\"><i>a</i></span>, which describes the arrangement after <span class=\"tex-span\"><i>t</i></span> seconds. If the <span class=\"tex-span\"><i>i</i></span>-th position has a boy after the needed time, then the <span class=\"tex-span\"><i>i</i></span>-th character <span class=\"tex-span\"><i>a</i></span> must equal \"<span class=\"tex-font-style-tt\">B</span>\", otherwise it must equal \"<span class=\"tex-font-style-tt\">G</span>\".</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 1<br/>BGGBG<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>GBGGB<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 2<br/>BGGBG<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>GGBGB<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 1<br/>GGGB<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>GGGB<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"c351b560da2cf2ec5b6797c8dbf9adad\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e5bd61caad7ef105f73513b491ec03004e7de55a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/266\">Codeforces Round 163 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='c351b560da2cf2ec5b6797c8dbf9adad'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/266/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Constructive algorithms\">\r\n constructive algorithms\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graph matchings, König's theorem, vertex cover of bipartite graph\">\r\n graph matchings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Shortest paths on weighted and unweighted graphs\">\r\n shortest paths\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='c351b560da2cf2ec5b6797c8dbf9adad'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2550\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" 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$(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6494\" title=\"Codeforces Round #163 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1457:1458\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6499\" title=\"Codeforces Round #163 (Div. 2) Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1693:1694\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/266\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/266/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/266/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/266/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/266/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/266/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/266/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/266/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 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</div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Queue at the School</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>During the break the schoolchildren, boys and girls, formed a queue of <span class=\"tex-span\"><i>n</i></span> people in the canteen. Initially the children stood in the order they entered the canteen. However, after a while the boys started feeling awkward for standing in front of the girls in the queue and they started letting the girls move forward each second. </p><p>Let's describe the process more precisely. Let's say that the positions in the queue are sequentially numbered by integers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>, at that the person in the position number <span class=\"tex-span\">1</span> is served first. Then, if at time <span class=\"tex-span\"><i>x</i></span> a boy stands on the <span class=\"tex-span\"><i>i</i></span>-th position and a girl stands on the <span class=\"tex-span\">(<i>i</i> + 1)</span>-th position, then at time <span class=\"tex-span\"><i>x</i> + 1</span> the <span class=\"tex-span\"><i>i</i></span>-th position will have a girl and the <span class=\"tex-span\">(<i>i</i> + 1)</span>-th position will have a boy. The time is given in seconds.</p><p>You've got the initial position of the children, at the initial moment of time. Determine the way the queue is going to look after <span class=\"tex-span\"><i>t</i></span> seconds.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>t</i> ≤ 50)</span>, which represent the number of children in the queue and the time after which the queue will transform into the arrangement you need to find. </p><p>The next line contains string <span class=\"tex-span\"><i>s</i></span>, which represents the schoolchildren's initial arrangement. If the <span class=\"tex-span\"><i>i</i></span>-th position in the queue contains a boy, then the <span class=\"tex-span\"><i>i</i></span>-th character of string <span class=\"tex-span\"><i>s</i></span> equals "<span class=\"tex-font-style-tt\">B</span>", otherwise the <span class=\"tex-span\"><i>i</i></span>-th character equals "<span class=\"tex-font-style-tt\">G</span>".</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print string <span class=\"tex-span\"><i>a</i></span>, which describes the arrangement after <span class=\"tex-span\"><i>t</i></span> seconds. If the <span class=\"tex-span\"><i>i</i></span>-th position has a boy after the needed time, then the <span class=\"tex-span\"><i>i</i></span>-th character <span class=\"tex-span\"><i>a</i></span> must equal "<span class=\"tex-font-style-tt\">B</span>", otherwise it must equal "<span class=\"tex-font-style-tt\">G</span>".</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 1<br />BGGBG<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>GBGGB<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 2<br />BGGBG<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>GGBGB<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 1<br />GGGB<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>GGGB<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='6a738ad05acb379636bd06c9a5923677'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6546\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6499\"> <p>Codeforces Round #163 (Div. 2) Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/266/problem/A\" title=\"Codeforces Round 163 (Div. 2)\">266A - Stones on the Table</a></p><p>In this problem you should count number of consecutive pairs of equal letters. It can be done using one cycle and <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> time.</p><p><a href=\"/contest/266/problem/B\" title=\"Codeforces Round 163 (Div. 2)\">266B - Queue at the School</a></p><p>In this you should realize the given process. You should <span class=\"tex-span\"><i>t</i></span> times swap elements <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i> + 1</span> if on the place <span class=\"tex-span\"><i>i</i></span> was a girl and on the place <span class=\"tex-span\"><i>i</i> + 1</span> was a boy. You should not push some girl to the left multiple times at once. The solution can be written using <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>T</i>)</span> time. </p><p><a href=\"/contest/266/problem/C\" title=\"Codeforces Round 163 (Div. 2)\">266C - Below the Diagonal</a></p><p>This problem can be solved using constructive algorithm. We will use inductive approach. At first, we have matrix of size <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>n</i> - 1</span> ones in it. Therefore, there is a column with no ones in it. So, we put this column to <span class=\"tex-span\"><i>n</i></span>-th place. In this case, the lower right element will be <span class=\"tex-span\">0</span>. Then find any row with at least one integer one and put it to the <span class=\"tex-span\"><i>n</i></span>-th place.</p><p>After these operations the element in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span> equals to <span class=\"tex-span\">0</span> and the last row has at least one integer one. Therefore, we can reduce the dimension of our problem, that is <span class=\"tex-span\"><i>n</i>: = <i>n</i> - 1</span>. In our new problem we have no more than <span class=\"tex-span\"><i>n</i> - 2</span> ones. So, we can solve this problem using the same algorithm. When <span class=\"tex-span\"><i>n</i></span> equals to <span class=\"tex-span\">1</span> you should finish algorithm, because there is no ones left. This algorithm uses <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> swap operations, no more than two for every <span class=\"tex-span\"><i>n</i></span>.</p><p><a href=\"/contest/266/problem/D\" title=\"Codeforces Round 163 (Div. 2)\">266D - BerDonalds</a></p><p>I'll tell a few ideas how to solve this problem. Firstly, describe the solution with time <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span>. Consider every edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> of length <span class=\"tex-span\"><i>len</i></span> where could be the answer point. Let this point lie at a distance <span class=\"tex-span\"><i>x</i></span> from vertex <span class=\"tex-span\"><i>u</i></span>. So, the distance from this point to vertex <span class=\"tex-span\"><i>i</i></span> would be <span class=\"tex-span\"><i>min</i>(<i>x</i> + <i>d</i>[<i>u</i>][<i>i</i>], <i>len</i>–<i>x</i> + <i>d</i>[<i>v</i>][<i>i</i>])</span>, where <span class=\"tex-span\"><i>d</i>[<i>x</i>][<i>y</i>]</span> — distance between vertices <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. Equate these values and get the critical value <span class=\"tex-span\"><i>x</i></span> for vertex <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\"><i>x</i> = (<i>len</i> + <i>d</i>[<i>v</i>][<i>i</i>]–<i>d</i>[<i>u</i>][<i>i</i>]) / 2</span>. It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations.</p><p>Another solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>·<i>log</i><sup class=\"upper-index\">2</sup>)</span>. Multiply all weights by <span class=\"tex-span\">2</span>. Consider every edge where should be the answer and make binary search for the answer (in integers). To check some current value you should consider every vertex <span class=\"tex-span\"><i>i</i></span> and assume that the answer is achieved in this vertex. In this case, the answer point must lie on this edge <= some value <span class=\"tex-span\"><i>l</i>[<i>i</i>]</span> or >= some value <span class=\"tex-span\"><i>r</i>[<i>i</i>]</span>. This subproblem is solved using offline algorithm using sorting events and maintaining the balance.</p><p>Also, you can use ternary search on every edge of the graph. But you should divide every edge on several segments and find the answer on every segment, because the ternary search is incorrect in this problem.</p><p>The last two solutions can provide accepted, if you realize them carefully. Also note, that there is the solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>)</span> by the author <a class=\"rated-user user-orange\" href=\"/profile/RAD\" title=\"International Master RAD\">RAD</a>.</p><p><a href=\"/contest/266/problem/E\" title=\"Codeforces Round 163 (Div. 2)\">266E - More Queries to Array...</a></p><p>This problem can be solved using data structure. We would use segment tree, we will support <span class=\"tex-span\"><i>k</i></span> segment trees for every power. At every vertex we will calculate weighted sum of the appropriate power, also we will save some number that indicates the color of the whole segment, if any.</p><p>User <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> in comments to the post and user <a class=\"rated-user user-violet\" href=\"/profile/mexmans\" title=\"Candidate Master mexmans\">mexmans</a> in comments to the tutorial tell their formula to get the answer. I try to describe how to get them by yourself. Firstly, you should write what value your segment tree gives. The tree can calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a5b58e8b23c7841d1d63b86cb9dff69967de47a9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. You need to calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c643f7f8655fd5b92fece5daa272e472e6c8f830.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, you can write it also as <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6328f7eee132b5640555cc7d5315c4a3b3a21417.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then you should write the last sum for some first powers (at least three) (at piece of paper) and subtract the second sum (what you need) from the first sum (what your tree can calculate). You get an expression that describes what should be subtracted to get the answer from the value what you tree can calculate. This is just the Newton binomial without the highest power.</p><p>So, the answer for power <span class=\"tex-span\"><i>j</i></span> is expressed as the subtraction of the value of query to your segment tree and the Newton binomial, with all powers that are less than <span class=\"tex-span\"><i>j</i></span> (these values can also calculated using your segment tree). Partial sum of the powers and binomial coefficients can be precalced. The solution has the complexity <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>K</i>·<i>log</i>(<i>N</i>))</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/266\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 163 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-6546\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"6499\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=163\" class=\"tag notice\" style=\"text-decoration: none;\">163</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+21</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6499#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6499#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6556\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (44)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119720\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119720\" href=\"?#comment-119720\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119720\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119720\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for d & e?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119720 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119720 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119720\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119734\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ximera\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57168/avatar/5b9093f6cb7c97f6.jpg'/> </a>\n <div><a href=\"/profile/Ximera\" title=\"Master Ximera\" class=\"rated-user user-orange\">Ximera</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:59\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119734\" href=\"?#comment-119734\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119734\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"57168\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119734\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Bit patience my friend :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119734 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119734 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119734\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119742\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 19:27\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119742\" href=\"?#comment-119742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119742\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It has not been ready yet.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119742\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119748\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xeronix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8425/avatar/b652c95a2089a33b.jpg'/> </a>\n <div><a href=\"/profile/xeronix\" title=\"Expert xeronix\" class=\"rated-user user-blue\">xeronix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 20:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119748\" href=\"?#comment-119748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119748\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"8425\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For D i tried the following approach but somehow couldn't finish debugging it. </p> <pre><code>For all those vertices v whose eccentricity == radius of graph:\n For all the adjoining edges of v i.e. edge(v,x):\n Binary Search for the location l on the edge (v,x) which minimizes graph \n radius considering l as a vertex\n Keep track of minimum of all such graph radii\n</code></pre><p>Will it work ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119748\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119774\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119774\" href=\"?#comment-119774\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119774\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119774\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C the important part is how can you find the 0 row fast (I mean the row with all numbers 0 in it), because you do it O(N) times and naive way (O(N^2)) is not sufficient. I used some dynamic arrays and updated them after each swap. For me the difficulty was in implementation and not in the algorithm, I got it in about 5 minutes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119774 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119774 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119774\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119776\" commentParentId=\"119774\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guliashvili\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39591/avatar/37cde92b05e59c05.jpg'/> </a>\n <div><a href=\"/profile/guliashvili\" title=\"Candidate Master guliashvili\" class=\"rated-user user-violet\">guliashvili</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119776\" href=\"?#comment-119776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119774\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n = 1000 whats the problem with n^2 algo?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119776\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119787\" commentParentId=\"119776\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 23:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119787\" href=\"?#comment-119787\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119776\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119787\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119787\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>you do N^2 thing O(N) times, in total it becomes O(N^3). I mean in O(N) times you will have to find 0 row in remaining square. That's not a straightforward thing to do, for me it was harder than the part that is written in the tutorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119787 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119787 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119787\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119789\" commentParentId=\"119787\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119789\" href=\"?#comment-119789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119787\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>you have O(n) phases (O(n) swaps to make):\n each phase you search for the appropriate column //O(n)\n you perform the swap in O(n)\n</code></pre><p>the two steps are independent, so this gives O(n^2), which is feasible. you just need an array of size n counting the number of ones in each column to search for the appropriate column in O(n)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119789\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119791\" commentParentId=\"119789\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119791\" href=\"?#comment-119791\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119789\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119791\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119791\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>that's what I did actually</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119791 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119791 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119791\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119777\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119777\" href=\"?#comment-119777\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119777\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119777\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D and E ? at least some hint ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119777 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119777 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119777\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119850\" commentParentId=\"119777\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kraskevich\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41036/avatar/baa5690e761857ad.jpg'/> </a>\n <div><a href=\"/profile/kraskevich\" title=\"International Grandmaster kraskevich\" class=\"rated-user user-red\">kraskevich</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:18\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119850\" href=\"?#comment-119850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119777\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119850\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"41036\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>E: 1) Let's understand how to solve this problem if k for all queries to calculate the sum is equal to 0. It's quite easy to do it: we can just use a segment tree.</p><p>2) Let's learn to answer queries where k is greater than zero. Let's assume that we know a correct answer for a node's left child and right child. We need to merge node's children answers. To do it, we can figure out the following formula: answer for current node and power k ans[k] = ans_left[k] + ans_right[k] + sum for all 1 <= j <= k ans_right[k — j] * L ^ j * c[k][j], where ans_left and ans_right are the answers for node's children, c[k][j] is a binomial coefficient and L is the length of a segment represented by the left child of the node.</p><p>3) However, we still don't know how to process assign queries. But this is rather simple: if we precalculate prefix sums for all powers, we'll be able to find a value for a certain node in a tree in constant time even if its value has been updated.</p><p>Such solutuion works in O(N + M log N) time. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120420\" commentParentId=\"119850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 07:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120420\" href=\"?#comment-120420\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120420\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120420\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks for the hint</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120420 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120420 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120420\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119792\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kotenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44176/avatar/7983fd66b7982a73.jpg'/> </a>\n <div><a href=\"/profile/Kotenko\" title=\"Specialist Kotenko\" class=\"rated-user user-cyan\">Kotenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119792\" href=\"?#comment-119792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119792\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44176\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems that I had underestimated the C problem — very interesting idea to solve it.<br />Thanks for tutorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119792\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119793\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stifff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78162/avatar/af74a0645f71a854.jpg'/> </a>\n <div><a href=\"/profile/stifff\" title=\"Specialist stifff\" class=\"rated-user user-cyan\">stifff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119793\" href=\"?#comment-119793\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119793\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78162\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119793\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could I solve D Problem, using Hakimi algo, for searching an absolute center of Graph?</p><p>Article in Russian is here:</p><p><a href=\"http://www.uchimatchast.ru/teory/abs_center.php\">http://www.uchimatchast.ru/teory/abs_center.php</a></p><p>(algo in the bottom of the page)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119793 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119793 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119793\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119794\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/howsiwei\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/howsiwei\" title=\"Candidate Master howsiwei\" class=\"rated-user user-violet\">howsiwei</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 04:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119794\" href=\"?#comment-119794\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119794\" revisionCount=\"8\" revision=\"8\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">8</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119794\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77740\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119794\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem C there is an O(n) solution. <a href=\"/contest/266/submission/2997252\" title=\"Submission 2997252 by howsiwei\">2997252</a> (this is not my original idea, i learnt it from <a href=\"/contest/266/submission/2993213\" title=\"Submission 2993213 by tjsudys\">2993213</a> and edit the swap part to make it O(n)) The main idea is that after j steps, for all 1<k<=j, kth marked cell will lies in column 1 to k, row c+1(c=its column number) to j+1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119794 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119794 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119794\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119808\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:13\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119808\" href=\"?#comment-119808\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119808\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119808\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119808\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119808 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119808 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119808\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119809\" commentParentId=\"119808\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iensen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/iensen\" title=\"Candidate Master iensen\" class=\"rated-user user-violet\">iensen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119809\" href=\"?#comment-119809\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119808\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119809\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"504\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119809\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You are right that two swaps are needed, but by <a href=\"https://en.wikipedia.org/wiki/Big_O_notation\">definition of Big-O notation</a>, there is no difference between O(N) and O(2*N). O(N) means there is some fixed constant M such that algorithm works in time M*N for each input of any size N. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119809 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119809 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119809\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119813\" commentParentId=\"119809\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 12:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119813\" href=\"?#comment-119813\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119809\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119813\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119813\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119813\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119813 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119813 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119813\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119821\" commentParentId=\"119813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ramint\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/74825/avatar/8a16585522c3dce2.jpg'/> </a>\n <div><a href=\"/profile/ramint\" title=\"Newbie ramint\" class=\"rated-user user-gray\">ramint</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119821\" href=\"?#comment-119821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"74825\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>but it doesnt mean ,your swaps take o(2*n) ......</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119821\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119822\" commentParentId=\"119821\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119822\" href=\"?#comment-119822\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119821\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119822\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119822\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119822\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119822 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119822 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119822\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119811\" href=\"?#comment-119811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Tutorial for chinese version <a href=\"http://blog.csdn.net/haha593572013/article/details/8538216\">chick here</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119811\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119840\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 17:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119840\" href=\"?#comment-119840\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119840\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119840\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My idea for problem D is using ford-bellman, then with every edge[i], I find the furthest way from edge[i].x, from edge[i].y without pass through the edge[i] and determine the point, but I get WA. Anyone can explain, or have a wrong test case for that ? Thank you for helping, and sorry for my poor english :).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119840 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119840 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119840\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119845\" commentParentId=\"119840\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 18:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119845\" href=\"?#comment-119845\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119840\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119845\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119845\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>open your submission, you'll find the test cases below your code, and you'll find the one that gives your WA.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119845 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119845 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119845\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119848\" commentParentId=\"119845\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119848\" href=\"?#comment-119848\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119845\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119848\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119848\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know about that, but that one is too big.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119848 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119848 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119848\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119854\" commentParentId=\"119848\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119854\" href=\"?#comment-119854\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119848\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119854\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119854\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119854\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How do you determinate the point on edge? You can't use ternary search, because function on it isn't convex</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119854 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119854 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119854\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119856\" commentParentId=\"119854\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119856\" href=\"?#comment-119856\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119854\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119856\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119856\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>point = ( furthest(edge[i].x) — furthest(edge[i].y) + edge[i].w )/2; Is it right ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119856 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119856 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119856\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119861\" commentParentId=\"119856\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:43\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119861\" href=\"?#comment-119861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119856\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, it isn't. I thought so too, but <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> said me, that function on the edge is piece-wise linear. So you must disintegrate it on the segments. I'm still thinking, how to do it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120017\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:37\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120017\" href=\"?#comment-120017\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120017\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120017\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a Monotonicity when the answer(ans) is increasing , you will find more such points that satisfy the condition Max_shortest_distance <= ans,so i think you can try binary search of this problem .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120017 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120017 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120017\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120171\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 14:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120171\" href=\"?#comment-120171\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120171\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120171\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have you passed the solution? If yes, please write the idea :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120171 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120171 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120171\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120000\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21339/avatar/58866417a0c9f963.jpg'/> </a>\n <div><a href=\"/profile/irakli\" title=\"Specialist irakli\" class=\"rated-user user-cyan\">irakli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2013 22:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120000\" href=\"?#comment-120000\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120000\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"36\"\r\n data-commentUserId=\"21339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+36</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120000\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Still waiting for D and E solutions...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120000 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120000 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120000\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120016\" commentParentId=\"120000\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mosiomohsen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42052/avatar/5d107e4760b3f346.jpg'/> </a>\n <div><a href=\"/profile/mosiomohsen\" title=\"Specialist mosiomohsen\" class=\"rated-user user-cyan\">mosiomohsen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120016\" href=\"?#comment-120016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120000\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"42052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>:-w</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120016\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120042\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/vinaybajaj2610\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25881/avatar/4c912eb678ab859d.jpg'/> </a>\n <div><a href=\"/profile/vinaybajaj2610\" title=\"Expert vinaybajaj2610\" class=\"rated-user user-blue\">vinaybajaj2610</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 15:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120042\" href=\"?#comment-120042\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120042\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"25881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120042\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you also should provide the link to good code for each problem in contest with each problems explanation in tutorial. [ Best : Good and nice implementation and better complexity]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120042 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120042 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120042\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120059\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tjsumonster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82432/avatar/dfcbf8967ac2147c.jpg'/> </a>\n <div><a href=\"/profile/tjsumonster\" title=\"Expert tjsumonster\" class=\"rated-user user-blue\">tjsumonster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 16:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120059\" href=\"?#comment-120059\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120059\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"82432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120059\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for D & E pls!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120059 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120059 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120059\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120223\" commentParentId=\"120059\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tctony\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3000/avatar/c90abcf148ccb4c.jpg'/> </a>\n <div><a href=\"/profile/tctony\" title=\"Specialist tctony\" class=\"rated-user user-cyan\">tctony</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 08:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120223\" href=\"?#comment-120223\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120059\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120223\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"3000\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120223\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find editorial for D from problem C at <a href=\"http://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">here</a>.</p><p>Hope someone can do some explanation on E!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120223 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120223 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120223\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120275\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 19:03\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120275\" href=\"?#comment-120275\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120275\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120275\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks, nice explanation of problem D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120275 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120275 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120275\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121286\" commentParentId=\"120275\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 00:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121286\" href=\"?#comment-121286\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120275\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121286\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121286\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry but I don't think so: In the discussion of D we read: " It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations." I don't think that it is true for the 3-rd example. Even if not so, the proof is quite ambiguous. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121286 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121286 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121286\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120429\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120429\" href=\"?#comment-120429\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120429\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120429\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>whats that?</p><p>there are only solutions. where to read problems ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120429 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120429 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120429\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121254\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2013 17:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121254\" href=\"?#comment-121254\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121254\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121254\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121254\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121254 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121254 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121254\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"547929\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2019 20:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-547929\" href=\"?#comment-547929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"547929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-547929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great source for learning the Min. Diameter Spanning Tree but the link seems to be broken. Here's the web archive link for the pdf: <a href=\"https://web.archive.org/web/20160309101249/https://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">Link</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-547929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-547929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-547929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120230\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/husseincoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/5219/avatar/de8f1c32ce880839.jpg'/> </a>\n <div><a href=\"/profile/husseincoder\" title=\"Specialist husseincoder\" class=\"rated-user user-cyan\">husseincoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 14:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120230\" href=\"?#comment-120230\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120230\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5219\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120230\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my approach that gets WA.. but i don't know why..</p><p>First i compute the shortest distance between pairs using floyd warshal, then iterate all pairs getting the furthest node to each one of them.. then using binary search i get the optimal place on the road of those pair.. getting the min for every pair and printing it.</p><p>Can anybody tell me whats the problem of my solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120230 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120230 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120230\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"373902\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CaptainRubik_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/343348/avatar/19c785dbaef44419.jpg'/> </a>\n <div><a href=\"/profile/CaptainRubik_\" title=\"Pupil CaptainRubik_\" class=\"rated-user user-green\">CaptainRubik_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2017 05:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-373902\" href=\"?#comment-373902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"373902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"343348\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-373902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The tags for Div2B include Max flow. Can anyone elaborate on how to model this problem as a graph?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-373902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-373902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-373902\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"943288\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coder_firegun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1825864/avatar/c03899f54d682484.jpg'/> </a>\n <div><a href=\"/profile/coder_firegun\" title=\"Pupil coder_firegun\" class=\"rated-user user-green\">coder_firegun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/15/2022 11:23\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-943288\" href=\"?#comment-943288\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"943288\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1825864\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-943288\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve problem B when constraints are large using graphs as mentioned in problem tags</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-943288 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-943288 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-943288\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966578\" commentParentId=\"943288\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/diwaseharsh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/diwaseharsh\" title=\"Newbie diwaseharsh\" class=\"rated-user user-gray\">diwaseharsh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 10:24\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966578\" href=\"?#comment-966578\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-943288\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966578\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2517510\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966578\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also wanna know. but i dont know maps ...</p><p>can U share ur code??????</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966578 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966578 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966578\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1027114\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepaksolution\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/deepaksolution\" title=\"Unrated, deepaksolution\" class=\"rated-user user-black\">deepaksolution</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/03/2023 20:15\">5 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1027114\" href=\"?#comment-1027114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1027114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3184366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1027114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Solution of 266B — Queue at the School Is Here in the below link with explanation of code</strong></p><p><a href=\"https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html\">https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply 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Below the Diagonal"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Below the Diagonal</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given a square matrix consisting of <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns. We assume that the rows are numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from top to bottom and the columns are numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Some cells (<span class=\"tex-span\"><i>n</i> - 1</span> cells in total) of the the matrix are filled with ones, the remaining cells are filled with zeros. We can apply the following operations to the matrix:</p><ol> <li> Swap <span class=\"tex-span\"><i>i</i></span>-th and <span class=\"tex-span\"><i>j</i></span>-th rows of the matrix; </li><li> Swap <span class=\"tex-span\"><i>i</i></span>-th and <span class=\"tex-span\"><i>j</i></span>-th columns of the matrix. </li></ol><p>You are asked to transform the matrix into a special form using these operations. In that special form all the ones must be in the cells that lie below the main diagonal. Cell of the matrix, which is located on the intersection of the <span class=\"tex-span\"><i>i</i></span>-th row and of the <span class=\"tex-span\"><i>j</i></span>-th column, lies below the main diagonal if <span class=\"tex-span\"><i>i</i> > <i>j</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(2 ≤ <i>n</i> ≤ 1000)</span> — the number of rows and columns. Then follow <span class=\"tex-span\"><i>n</i> - 1</span> lines that contain one's positions, one per line. Each position is described by two integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>k</i></sub>, <i>y</i><sub class=\"lower-index\"><i>k</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>x</i><sub class=\"lower-index\"><i>k</i></sub>, <i>y</i><sub class=\"lower-index\"><i>k</i></sub> ≤ <i>n</i>)</span>, separated by a space. A pair <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>k</i></sub>, <i>y</i><sub class=\"lower-index\"><i>k</i></sub>)</span> means that the cell, which is located on the intersection of the <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>k</i></sub></span>-th row and of the <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>k</i></sub></span>-th column, contains one.</p><p>It is guaranteed that all positions are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print the description of your actions. These actions should transform the matrix to the described special form.</p><p>In the first line you should print a non-negative integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(<i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of actions. In each of the next <span class=\"tex-span\"><i>m</i></span> lines print three space-separated integers <span class=\"tex-span\"><i>t</i>, <i>i</i>, <i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>t</i> ≤ 2, 1 ≤ <i>i</i>, <i>j</i> ≤ <i>n</i>, <i>i</i> ≠ <i>j</i>)</span>, where <span class=\"tex-span\"><i>t</i> = 1</span> if you want to swap rows, <span class=\"tex-span\"><i>t</i> = 2</span> if you want to swap columns, and <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> denote the numbers of rows or columns respectively.</p><p>Please note, that you do not need to minimize the number of operations, but their number should not exceed <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>. If there are several solutions, you may print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/>2 1 2<br/>1 1 2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>3 1<br/>1 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>2 2 3<br/>1 1 3<br/>1 1 2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>2 1<br/>3 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"a4d7dd195a37d9d3bde269c4dd85bbc9\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e5bd61caad7ef105f73513b491ec03004e7de55a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/266\">Codeforces Round 163 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/266/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Constructive algorithms\">\r\n constructive algorithms\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" 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}\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_8c4a119e058124ddc01f0c02950d4a2e634a630e\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Below the Diagonal</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given a square matrix consisting of <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>n</i></span> columns. We assume that the rows are numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from top to bottom and the columns are numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. Some cells (<span class=\"tex-span\"><i>n</i> - 1</span> cells in total) of the the matrix are filled with ones, the remaining cells are filled with zeros. We can apply the following operations to the matrix:</p><ol> <li> Swap <span class=\"tex-span\"><i>i</i></span>-th and <span class=\"tex-span\"><i>j</i></span>-th rows of the matrix; </li><li> Swap <span class=\"tex-span\"><i>i</i></span>-th and <span class=\"tex-span\"><i>j</i></span>-th columns of the matrix. </li></ol><p>You are asked to transform the matrix into a special form using these operations. In that special form all the ones must be in the cells that lie below the main diagonal. Cell of the matrix, which is located on the intersection of the <span class=\"tex-span\"><i>i</i></span>-th row and of the <span class=\"tex-span\"><i>j</i></span>-th column, lies below the main diagonal if <span class=\"tex-span\"><i>i</i> > <i>j</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(2 ≤ <i>n</i> ≤ 1000)</span> — the number of rows and columns. Then follow <span class=\"tex-span\"><i>n</i> - 1</span> lines that contain one's positions, one per line. Each position is described by two integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>k</i></sub>, <i>y</i><sub class=\"lower-index\"><i>k</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>x</i><sub class=\"lower-index\"><i>k</i></sub>, <i>y</i><sub class=\"lower-index\"><i>k</i></sub> ≤ <i>n</i>)</span>, separated by a space. A pair <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>k</i></sub>, <i>y</i><sub class=\"lower-index\"><i>k</i></sub>)</span> means that the cell, which is located on the intersection of the <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>k</i></sub></span>-th row and of the <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>k</i></sub></span>-th column, contains one.</p><p>It is guaranteed that all positions are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print the description of your actions. These actions should transform the matrix to the described special form.</p><p>In the first line you should print a non-negative integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(<i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of actions. In each of the next <span class=\"tex-span\"><i>m</i></span> lines print three space-separated integers <span class=\"tex-span\"><i>t</i>, <i>i</i>, <i>j</i></span> <span class=\"tex-span\">(1 ≤ <i>t</i> ≤ 2, 1 ≤ <i>i</i>, <i>j</i> ≤ <i>n</i>, <i>i</i> ≠ <i>j</i>)</span>, where <span class=\"tex-span\"><i>t</i> = 1</span> if you want to swap rows, <span class=\"tex-span\"><i>t</i> = 2</span> if you want to swap columns, and <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>j</i></span> denote the numbers of rows or columns respectively.</p><p>Please note, that you do not need to minimize the number of operations, but their number should not exceed <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>. If there are several solutions, you may print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br />2 1 2<br />1 1 2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />3 1<br />1 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />2 2 3<br />1 1 3<br />1 1 2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />2 1<br />3 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='6a738ad05acb379636bd06c9a5923677'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final 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href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6546\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6499\"> <p>Codeforces Round #163 (Div. 2) Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/266/problem/A\" title=\"Codeforces Round 163 (Div. 2)\">266A - Stones on the Table</a></p><p>In this problem you should count number of consecutive pairs of equal letters. It can be done using one cycle and <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> time.</p><p><a href=\"/contest/266/problem/B\" title=\"Codeforces Round 163 (Div. 2)\">266B - Queue at the School</a></p><p>In this you should realize the given process. You should <span class=\"tex-span\"><i>t</i></span> times swap elements <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i> + 1</span> if on the place <span class=\"tex-span\"><i>i</i></span> was a girl and on the place <span class=\"tex-span\"><i>i</i> + 1</span> was a boy. You should not push some girl to the left multiple times at once. The solution can be written using <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>T</i>)</span> time. </p><p><a href=\"/contest/266/problem/C\" title=\"Codeforces Round 163 (Div. 2)\">266C - Below the Diagonal</a></p><p>This problem can be solved using constructive algorithm. We will use inductive approach. At first, we have matrix of size <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>n</i> - 1</span> ones in it. Therefore, there is a column with no ones in it. So, we put this column to <span class=\"tex-span\"><i>n</i></span>-th place. In this case, the lower right element will be <span class=\"tex-span\">0</span>. Then find any row with at least one integer one and put it to the <span class=\"tex-span\"><i>n</i></span>-th place.</p><p>After these operations the element in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span> equals to <span class=\"tex-span\">0</span> and the last row has at least one integer one. Therefore, we can reduce the dimension of our problem, that is <span class=\"tex-span\"><i>n</i>: = <i>n</i> - 1</span>. In our new problem we have no more than <span class=\"tex-span\"><i>n</i> - 2</span> ones. So, we can solve this problem using the same algorithm. When <span class=\"tex-span\"><i>n</i></span> equals to <span class=\"tex-span\">1</span> you should finish algorithm, because there is no ones left. This algorithm uses <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> swap operations, no more than two for every <span class=\"tex-span\"><i>n</i></span>.</p><p><a href=\"/contest/266/problem/D\" title=\"Codeforces Round 163 (Div. 2)\">266D - BerDonalds</a></p><p>I'll tell a few ideas how to solve this problem. Firstly, describe the solution with time <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span>. Consider every edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> of length <span class=\"tex-span\"><i>len</i></span> where could be the answer point. Let this point lie at a distance <span class=\"tex-span\"><i>x</i></span> from vertex <span class=\"tex-span\"><i>u</i></span>. So, the distance from this point to vertex <span class=\"tex-span\"><i>i</i></span> would be <span class=\"tex-span\"><i>min</i>(<i>x</i> + <i>d</i>[<i>u</i>][<i>i</i>], <i>len</i>–<i>x</i> + <i>d</i>[<i>v</i>][<i>i</i>])</span>, where <span class=\"tex-span\"><i>d</i>[<i>x</i>][<i>y</i>]</span> — distance between vertices <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. Equate these values and get the critical value <span class=\"tex-span\"><i>x</i></span> for vertex <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\"><i>x</i> = (<i>len</i> + <i>d</i>[<i>v</i>][<i>i</i>]–<i>d</i>[<i>u</i>][<i>i</i>]) / 2</span>. It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations.</p><p>Another solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>·<i>log</i><sup class=\"upper-index\">2</sup>)</span>. Multiply all weights by <span class=\"tex-span\">2</span>. Consider every edge where should be the answer and make binary search for the answer (in integers). To check some current value you should consider every vertex <span class=\"tex-span\"><i>i</i></span> and assume that the answer is achieved in this vertex. In this case, the answer point must lie on this edge <= some value <span class=\"tex-span\"><i>l</i>[<i>i</i>]</span> or >= some value <span class=\"tex-span\"><i>r</i>[<i>i</i>]</span>. This subproblem is solved using offline algorithm using sorting events and maintaining the balance.</p><p>Also, you can use ternary search on every edge of the graph. But you should divide every edge on several segments and find the answer on every segment, because the ternary search is incorrect in this problem.</p><p>The last two solutions can provide accepted, if you realize them carefully. Also note, that there is the solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>)</span> by the author <a class=\"rated-user user-orange\" href=\"/profile/RAD\" title=\"International Master RAD\">RAD</a>.</p><p><a href=\"/contest/266/problem/E\" title=\"Codeforces Round 163 (Div. 2)\">266E - More Queries to Array...</a></p><p>This problem can be solved using data structure. We would use segment tree, we will support <span class=\"tex-span\"><i>k</i></span> segment trees for every power. At every vertex we will calculate weighted sum of the appropriate power, also we will save some number that indicates the color of the whole segment, if any.</p><p>User <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> in comments to the post and user <a class=\"rated-user user-violet\" href=\"/profile/mexmans\" title=\"Candidate Master mexmans\">mexmans</a> in comments to the tutorial tell their formula to get the answer. I try to describe how to get them by yourself. Firstly, you should write what value your segment tree gives. The tree can calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a5b58e8b23c7841d1d63b86cb9dff69967de47a9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. You need to calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c643f7f8655fd5b92fece5daa272e472e6c8f830.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, you can write it also as <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6328f7eee132b5640555cc7d5315c4a3b3a21417.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then you should write the last sum for some first powers (at least three) (at piece of paper) and subtract the second sum (what you need) from the first sum (what your tree can calculate). You get an expression that describes what should be subtracted to get the answer from the value what you tree can calculate. This is just the Newton binomial without the highest power.</p><p>So, the answer for power <span class=\"tex-span\"><i>j</i></span> is expressed as the subtraction of the value of query to your segment tree and the Newton binomial, with all powers that are less than <span class=\"tex-span\"><i>j</i></span> (these values can also calculated using your segment tree). Partial sum of the powers and binomial coefficients can be precalced. The solution has the complexity <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>K</i>·<i>log</i>(<i>N</i>))</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/266\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 163 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-6546\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"6499\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=163\" class=\"tag notice\" style=\"text-decoration: none;\">163</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+21</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6499#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6499#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6556\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (44)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119720\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119720\" href=\"?#comment-119720\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119720\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119720\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for d & e?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119720 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119720 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119720\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119734\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ximera\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57168/avatar/5b9093f6cb7c97f6.jpg'/> </a>\n <div><a href=\"/profile/Ximera\" title=\"Master Ximera\" class=\"rated-user user-orange\">Ximera</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:59\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119734\" href=\"?#comment-119734\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119734\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"57168\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119734\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Bit patience my friend :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119734 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119734 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119734\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119742\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 19:27\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119742\" href=\"?#comment-119742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119742\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It has not been ready yet.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119742\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119748\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xeronix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8425/avatar/b652c95a2089a33b.jpg'/> </a>\n <div><a href=\"/profile/xeronix\" title=\"Expert xeronix\" class=\"rated-user user-blue\">xeronix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 20:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119748\" href=\"?#comment-119748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119748\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"8425\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For D i tried the following approach but somehow couldn't finish debugging it. </p> <pre><code>For all those vertices v whose eccentricity == radius of graph:\n For all the adjoining edges of v i.e. edge(v,x):\n Binary Search for the location l on the edge (v,x) which minimizes graph \n radius considering l as a vertex\n Keep track of minimum of all such graph radii\n</code></pre><p>Will it work ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119748\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119774\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119774\" href=\"?#comment-119774\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119774\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119774\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C the important part is how can you find the 0 row fast (I mean the row with all numbers 0 in it), because you do it O(N) times and naive way (O(N^2)) is not sufficient. I used some dynamic arrays and updated them after each swap. For me the difficulty was in implementation and not in the algorithm, I got it in about 5 minutes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119774 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119774 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119774\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119776\" commentParentId=\"119774\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guliashvili\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39591/avatar/37cde92b05e59c05.jpg'/> </a>\n <div><a href=\"/profile/guliashvili\" title=\"Candidate Master guliashvili\" class=\"rated-user user-violet\">guliashvili</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119776\" href=\"?#comment-119776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119774\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n = 1000 whats the problem with n^2 algo?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119776\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119787\" commentParentId=\"119776\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 23:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119787\" href=\"?#comment-119787\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119776\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119787\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119787\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>you do N^2 thing O(N) times, in total it becomes O(N^3). I mean in O(N) times you will have to find 0 row in remaining square. That's not a straightforward thing to do, for me it was harder than the part that is written in the tutorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119787 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119787 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119787\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119789\" commentParentId=\"119787\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119789\" href=\"?#comment-119789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119787\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>you have O(n) phases (O(n) swaps to make):\n each phase you search for the appropriate column //O(n)\n you perform the swap in O(n)\n</code></pre><p>the two steps are independent, so this gives O(n^2), which is feasible. you just need an array of size n counting the number of ones in each column to search for the appropriate column in O(n)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119789\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119791\" commentParentId=\"119789\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119791\" href=\"?#comment-119791\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119789\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119791\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119791\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>that's what I did actually</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119791 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119791 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119791\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119777\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119777\" href=\"?#comment-119777\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119777\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119777\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D and E ? at least some hint ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119777 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119777 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119777\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119850\" commentParentId=\"119777\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kraskevich\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41036/avatar/baa5690e761857ad.jpg'/> </a>\n <div><a href=\"/profile/kraskevich\" title=\"International Grandmaster kraskevich\" class=\"rated-user user-red\">kraskevich</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:18\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119850\" href=\"?#comment-119850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119777\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119850\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"41036\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>E: 1) Let's understand how to solve this problem if k for all queries to calculate the sum is equal to 0. It's quite easy to do it: we can just use a segment tree.</p><p>2) Let's learn to answer queries where k is greater than zero. Let's assume that we know a correct answer for a node's left child and right child. We need to merge node's children answers. To do it, we can figure out the following formula: answer for current node and power k ans[k] = ans_left[k] + ans_right[k] + sum for all 1 <= j <= k ans_right[k — j] * L ^ j * c[k][j], where ans_left and ans_right are the answers for node's children, c[k][j] is a binomial coefficient and L is the length of a segment represented by the left child of the node.</p><p>3) However, we still don't know how to process assign queries. But this is rather simple: if we precalculate prefix sums for all powers, we'll be able to find a value for a certain node in a tree in constant time even if its value has been updated.</p><p>Such solutuion works in O(N + M log N) time. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120420\" commentParentId=\"119850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 07:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120420\" href=\"?#comment-120420\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120420\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120420\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks for the hint</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120420 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120420 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120420\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119792\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kotenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44176/avatar/7983fd66b7982a73.jpg'/> </a>\n <div><a href=\"/profile/Kotenko\" title=\"Specialist Kotenko\" class=\"rated-user user-cyan\">Kotenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119792\" href=\"?#comment-119792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119792\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44176\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems that I had underestimated the C problem — very interesting idea to solve it.<br />Thanks for tutorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119792\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119793\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stifff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78162/avatar/af74a0645f71a854.jpg'/> </a>\n <div><a href=\"/profile/stifff\" title=\"Specialist stifff\" class=\"rated-user user-cyan\">stifff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119793\" href=\"?#comment-119793\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119793\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78162\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119793\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could I solve D Problem, using Hakimi algo, for searching an absolute center of Graph?</p><p>Article in Russian is here:</p><p><a href=\"http://www.uchimatchast.ru/teory/abs_center.php\">http://www.uchimatchast.ru/teory/abs_center.php</a></p><p>(algo in the bottom of the page)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119793 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119793 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119793\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119794\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/howsiwei\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/howsiwei\" title=\"Candidate Master howsiwei\" class=\"rated-user user-violet\">howsiwei</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 04:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119794\" href=\"?#comment-119794\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119794\" revisionCount=\"8\" revision=\"8\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">8</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119794\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77740\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119794\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem C there is an O(n) solution. <a href=\"/contest/266/submission/2997252\" title=\"Submission 2997252 by howsiwei\">2997252</a> (this is not my original idea, i learnt it from <a href=\"/contest/266/submission/2993213\" title=\"Submission 2993213 by tjsudys\">2993213</a> and edit the swap part to make it O(n)) The main idea is that after j steps, for all 1<k<=j, kth marked cell will lies in column 1 to k, row c+1(c=its column number) to j+1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119794 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119794 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119794\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119808\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:13\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119808\" href=\"?#comment-119808\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119808\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119808\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119808\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119808 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119808 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119808\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119809\" commentParentId=\"119808\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iensen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/iensen\" title=\"Candidate Master iensen\" class=\"rated-user user-violet\">iensen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119809\" href=\"?#comment-119809\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119808\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119809\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"504\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119809\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You are right that two swaps are needed, but by <a href=\"https://en.wikipedia.org/wiki/Big_O_notation\">definition of Big-O notation</a>, there is no difference between O(N) and O(2*N). O(N) means there is some fixed constant M such that algorithm works in time M*N for each input of any size N. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119809 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119809 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119809\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119813\" commentParentId=\"119809\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 12:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119813\" href=\"?#comment-119813\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119809\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119813\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119813\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119813\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119813 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119813 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119813\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119821\" commentParentId=\"119813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ramint\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/74825/avatar/8a16585522c3dce2.jpg'/> </a>\n <div><a href=\"/profile/ramint\" title=\"Newbie ramint\" class=\"rated-user user-gray\">ramint</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119821\" href=\"?#comment-119821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"74825\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>but it doesnt mean ,your swaps take o(2*n) ......</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119821\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119822\" commentParentId=\"119821\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119822\" href=\"?#comment-119822\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119821\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119822\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119822\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119822\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119822 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119822 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119822\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119811\" href=\"?#comment-119811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Tutorial for chinese version <a href=\"http://blog.csdn.net/haha593572013/article/details/8538216\">chick here</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119811\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119840\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 17:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119840\" href=\"?#comment-119840\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119840\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119840\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My idea for problem D is using ford-bellman, then with every edge[i], I find the furthest way from edge[i].x, from edge[i].y without pass through the edge[i] and determine the point, but I get WA. Anyone can explain, or have a wrong test case for that ? Thank you for helping, and sorry for my poor english :).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119840 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119840 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119840\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119845\" commentParentId=\"119840\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 18:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119845\" href=\"?#comment-119845\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119840\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119845\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119845\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>open your submission, you'll find the test cases below your code, and you'll find the one that gives your WA.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119845 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119845 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119845\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119848\" commentParentId=\"119845\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119848\" href=\"?#comment-119848\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119845\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119848\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119848\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know about that, but that one is too big.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119848 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119848 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119848\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119854\" commentParentId=\"119848\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119854\" href=\"?#comment-119854\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119848\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119854\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119854\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119854\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How do you determinate the point on edge? You can't use ternary search, because function on it isn't convex</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119854 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119854 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119854\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119856\" commentParentId=\"119854\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119856\" href=\"?#comment-119856\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119854\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119856\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119856\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>point = ( furthest(edge[i].x) — furthest(edge[i].y) + edge[i].w )/2; Is it right ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119856 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119856 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119856\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119861\" commentParentId=\"119856\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:43\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119861\" href=\"?#comment-119861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119856\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, it isn't. I thought so too, but <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> said me, that function on the edge is piece-wise linear. So you must disintegrate it on the segments. I'm still thinking, how to do it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120017\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:37\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120017\" href=\"?#comment-120017\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120017\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120017\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a Monotonicity when the answer(ans) is increasing , you will find more such points that satisfy the condition Max_shortest_distance <= ans,so i think you can try binary search of this problem .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120017 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120017 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120017\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120171\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 14:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120171\" href=\"?#comment-120171\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120171\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120171\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have you passed the solution? If yes, please write the idea :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120171 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120171 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120171\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120000\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21339/avatar/58866417a0c9f963.jpg'/> </a>\n <div><a href=\"/profile/irakli\" title=\"Specialist irakli\" class=\"rated-user user-cyan\">irakli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2013 22:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120000\" href=\"?#comment-120000\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120000\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"36\"\r\n data-commentUserId=\"21339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+36</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120000\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Still waiting for D and E solutions...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120000 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120000 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120000\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120016\" commentParentId=\"120000\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mosiomohsen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42052/avatar/5d107e4760b3f346.jpg'/> </a>\n <div><a href=\"/profile/mosiomohsen\" title=\"Specialist mosiomohsen\" class=\"rated-user user-cyan\">mosiomohsen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120016\" href=\"?#comment-120016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120000\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"42052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>:-w</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120016\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120042\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/vinaybajaj2610\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25881/avatar/4c912eb678ab859d.jpg'/> </a>\n <div><a href=\"/profile/vinaybajaj2610\" title=\"Expert vinaybajaj2610\" class=\"rated-user user-blue\">vinaybajaj2610</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 15:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120042\" href=\"?#comment-120042\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120042\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"25881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120042\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you also should provide the link to good code for each problem in contest with each problems explanation in tutorial. [ Best : Good and nice implementation and better complexity]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120042 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120042 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120042\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120059\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tjsumonster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82432/avatar/dfcbf8967ac2147c.jpg'/> </a>\n <div><a href=\"/profile/tjsumonster\" title=\"Expert tjsumonster\" class=\"rated-user user-blue\">tjsumonster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 16:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120059\" href=\"?#comment-120059\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120059\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"82432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120059\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for D & E pls!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120059 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120059 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120059\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120223\" commentParentId=\"120059\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tctony\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3000/avatar/c90abcf148ccb4c.jpg'/> </a>\n <div><a href=\"/profile/tctony\" title=\"Specialist tctony\" class=\"rated-user user-cyan\">tctony</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 08:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120223\" href=\"?#comment-120223\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120059\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120223\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"3000\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120223\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find editorial for D from problem C at <a href=\"http://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">here</a>.</p><p>Hope someone can do some explanation on E!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120223 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120223 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120223\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120275\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 19:03\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120275\" href=\"?#comment-120275\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120275\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120275\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks, nice explanation of problem D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120275 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120275 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120275\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121286\" commentParentId=\"120275\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 00:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121286\" href=\"?#comment-121286\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120275\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121286\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121286\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry but I don't think so: In the discussion of D we read: " It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations." I don't think that it is true for the 3-rd example. Even if not so, the proof is quite ambiguous. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121286 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121286 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121286\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120429\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120429\" href=\"?#comment-120429\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120429\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120429\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>whats that?</p><p>there are only solutions. where to read problems ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120429 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120429 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120429\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121254\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2013 17:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121254\" href=\"?#comment-121254\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121254\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121254\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121254\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121254 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121254 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121254\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"547929\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2019 20:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-547929\" href=\"?#comment-547929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"547929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-547929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great source for learning the Min. Diameter Spanning Tree but the link seems to be broken. Here's the web archive link for the pdf: <a href=\"https://web.archive.org/web/20160309101249/https://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">Link</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-547929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-547929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-547929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120230\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/husseincoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/5219/avatar/de8f1c32ce880839.jpg'/> </a>\n <div><a href=\"/profile/husseincoder\" title=\"Specialist husseincoder\" class=\"rated-user user-cyan\">husseincoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 14:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120230\" href=\"?#comment-120230\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120230\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5219\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120230\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my approach that gets WA.. but i don't know why..</p><p>First i compute the shortest distance between pairs using floyd warshal, then iterate all pairs getting the furthest node to each one of them.. then using binary search i get the optimal place on the road of those pair.. getting the min for every pair and printing it.</p><p>Can anybody tell me whats the problem of my solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120230 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120230 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120230\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"373902\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CaptainRubik_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/343348/avatar/19c785dbaef44419.jpg'/> </a>\n <div><a href=\"/profile/CaptainRubik_\" title=\"Pupil CaptainRubik_\" class=\"rated-user user-green\">CaptainRubik_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2017 05:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-373902\" href=\"?#comment-373902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"373902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"343348\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-373902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The tags for Div2B include Max flow. Can anyone elaborate on how to model this problem as a graph?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-373902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-373902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-373902\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"943288\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coder_firegun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1825864/avatar/c03899f54d682484.jpg'/> </a>\n <div><a href=\"/profile/coder_firegun\" title=\"Pupil coder_firegun\" class=\"rated-user user-green\">coder_firegun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/15/2022 11:23\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-943288\" href=\"?#comment-943288\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"943288\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1825864\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-943288\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve problem B when constraints are large using graphs as mentioned in problem tags</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-943288 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-943288 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-943288\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966578\" commentParentId=\"943288\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/diwaseharsh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/diwaseharsh\" title=\"Newbie diwaseharsh\" class=\"rated-user user-gray\">diwaseharsh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 10:24\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966578\" href=\"?#comment-966578\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-943288\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966578\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2517510\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966578\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also wanna know. but i dont know maps ...</p><p>can U share ur code??????</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966578 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966578 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966578\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1027114\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepaksolution\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/deepaksolution\" title=\"Unrated, deepaksolution\" class=\"rated-user user-black\">deepaksolution</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/03/2023 20:15\">5 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1027114\" href=\"?#comment-1027114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1027114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3184366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1027114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Solution of 266B — Queue at the School Is Here in the below link with explanation of code</strong></p><p><a href=\"https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html\">https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply 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BerDonalds"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. BerDonalds</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>BerDonalds, a well-known fast food restaurant, is going to open a cafe in Bertown. The important thing is to choose the new restaurant's location so that it would be easy to get there. The Bertown road system is represented by <span class=\"tex-span\"><i>n</i></span> junctions, connected by <span class=\"tex-span\"><i>m</i></span> bidirectional roads. For each road we know its length. We also know that we can get from any junction to any other one, moving along the roads.</p><p>Your task is to find such location of the restaurant, that the shortest distance along the roads from the cafe to the farthest junction would be minimum. Note that the restaurant can be located not only on the junction, but at any point of any road.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e77c9ba339b03020eea469a8624f475d88cf28b8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>) — the number of junctions and the number of roads, correspondingly. Then <span class=\"tex-span\"><i>m</i></span> lines follow, describing all Bertown roads. Each road is described by three integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub>, <i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>, <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub>; 1 ≤ <i>w</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">5</sup></span>), where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> are the numbers of the junctions, connected by the <span class=\"tex-span\"><i>i</i></span>-th road, and <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> is the length of the <span class=\"tex-span\"><i>i</i></span>-th road. </p><p>It is guaranteed that each road connects two distinct junctions, there is at most one road between any two junctions, and you can get from any junction to any other one.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single real number — the shortest distance from the optimal restaurant location to the farthest junction. The answer will be considered correct, if its absolute or relative error doesn't exceed <span class=\"tex-span\">10<sup class=\"upper-index\"> - 9</sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 1<br/>1 2 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0.50<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 2 1<br/>2 3 1<br/>1 3 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1.00<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br/>1 2 100<br/>2 3 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>50.50<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b2cf341668a1f7d276a35ae30c1455dc\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e5bd61caad7ef105f73513b491ec03004e7de55a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/266\">Codeforces Round 163 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='b2cf341668a1f7d276a35ae30c1455dc'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/266/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Shortest paths on weighted and unweighted graphs\">\r\n shortest paths\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2400\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='b2cf341668a1f7d276a35ae30c1455dc'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2552\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='b2cf341668a1f7d276a35ae30c1455dc'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2552\"/>\r\n <input name=\"tagName\" type=\"hidden\" 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}\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_baedf82a9c7883731d73f5460b22ef94d17e0e98\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. BerDonalds</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>BerDonalds, a well-known fast food restaurant, is going to open a cafe in Bertown. The important thing is to choose the new restaurant's location so that it would be easy to get there. The Bertown road system is represented by <span class=\"tex-span\"><i>n</i></span> junctions, connected by <span class=\"tex-span\"><i>m</i></span> bidirectional roads. For each road we know its length. We also know that we can get from any junction to any other one, moving along the roads.</p><p>Your task is to find such location of the restaurant, that the shortest distance along the roads from the cafe to the farthest junction would be minimum. Note that the restaurant can be located not only on the junction, but at any point of any road.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e77c9ba339b03020eea469a8624f475d88cf28b8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />) — the number of junctions and the number of roads, correspondingly. Then <span class=\"tex-span\"><i>m</i></span> lines follow, describing all Bertown roads. Each road is described by three integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub>, <i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>, <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub>; 1 ≤ <i>w</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">5</sup></span>), where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> are the numbers of the junctions, connected by the <span class=\"tex-span\"><i>i</i></span>-th road, and <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> is the length of the <span class=\"tex-span\"><i>i</i></span>-th road. </p><p>It is guaranteed that each road connects two distinct junctions, there is at most one road between any two junctions, and you can get from any junction to any other one.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single real number — the shortest distance from the optimal restaurant location to the farthest junction. The answer will be considered correct, if its absolute or relative error doesn't exceed <span class=\"tex-span\">10<sup class=\"upper-index\"> - 9</sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 1<br />1 2 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0.50<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 2 1<br />2 3 1<br />1 3 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1.00<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br />1 2 100<br />2 3 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>50.50<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='6a738ad05acb379636bd06c9a5923677'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6546\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6499\"> <p>Codeforces Round #163 (Div. 2) Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/266/problem/A\" title=\"Codeforces Round 163 (Div. 2)\">266A - Stones on the Table</a></p><p>In this problem you should count number of consecutive pairs of equal letters. It can be done using one cycle and <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> time.</p><p><a href=\"/contest/266/problem/B\" title=\"Codeforces Round 163 (Div. 2)\">266B - Queue at the School</a></p><p>In this you should realize the given process. You should <span class=\"tex-span\"><i>t</i></span> times swap elements <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i> + 1</span> if on the place <span class=\"tex-span\"><i>i</i></span> was a girl and on the place <span class=\"tex-span\"><i>i</i> + 1</span> was a boy. You should not push some girl to the left multiple times at once. The solution can be written using <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>T</i>)</span> time. </p><p><a href=\"/contest/266/problem/C\" title=\"Codeforces Round 163 (Div. 2)\">266C - Below the Diagonal</a></p><p>This problem can be solved using constructive algorithm. We will use inductive approach. At first, we have matrix of size <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>n</i> - 1</span> ones in it. Therefore, there is a column with no ones in it. So, we put this column to <span class=\"tex-span\"><i>n</i></span>-th place. In this case, the lower right element will be <span class=\"tex-span\">0</span>. Then find any row with at least one integer one and put it to the <span class=\"tex-span\"><i>n</i></span>-th place.</p><p>After these operations the element in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span> equals to <span class=\"tex-span\">0</span> and the last row has at least one integer one. Therefore, we can reduce the dimension of our problem, that is <span class=\"tex-span\"><i>n</i>: = <i>n</i> - 1</span>. In our new problem we have no more than <span class=\"tex-span\"><i>n</i> - 2</span> ones. So, we can solve this problem using the same algorithm. When <span class=\"tex-span\"><i>n</i></span> equals to <span class=\"tex-span\">1</span> you should finish algorithm, because there is no ones left. This algorithm uses <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> swap operations, no more than two for every <span class=\"tex-span\"><i>n</i></span>.</p><p><a href=\"/contest/266/problem/D\" title=\"Codeforces Round 163 (Div. 2)\">266D - BerDonalds</a></p><p>I'll tell a few ideas how to solve this problem. Firstly, describe the solution with time <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span>. Consider every edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> of length <span class=\"tex-span\"><i>len</i></span> where could be the answer point. Let this point lie at a distance <span class=\"tex-span\"><i>x</i></span> from vertex <span class=\"tex-span\"><i>u</i></span>. So, the distance from this point to vertex <span class=\"tex-span\"><i>i</i></span> would be <span class=\"tex-span\"><i>min</i>(<i>x</i> + <i>d</i>[<i>u</i>][<i>i</i>], <i>len</i>–<i>x</i> + <i>d</i>[<i>v</i>][<i>i</i>])</span>, where <span class=\"tex-span\"><i>d</i>[<i>x</i>][<i>y</i>]</span> — distance between vertices <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. Equate these values and get the critical value <span class=\"tex-span\"><i>x</i></span> for vertex <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\"><i>x</i> = (<i>len</i> + <i>d</i>[<i>v</i>][<i>i</i>]–<i>d</i>[<i>u</i>][<i>i</i>]) / 2</span>. It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations.</p><p>Another solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>·<i>log</i><sup class=\"upper-index\">2</sup>)</span>. Multiply all weights by <span class=\"tex-span\">2</span>. Consider every edge where should be the answer and make binary search for the answer (in integers). To check some current value you should consider every vertex <span class=\"tex-span\"><i>i</i></span> and assume that the answer is achieved in this vertex. In this case, the answer point must lie on this edge <= some value <span class=\"tex-span\"><i>l</i>[<i>i</i>]</span> or >= some value <span class=\"tex-span\"><i>r</i>[<i>i</i>]</span>. This subproblem is solved using offline algorithm using sorting events and maintaining the balance.</p><p>Also, you can use ternary search on every edge of the graph. But you should divide every edge on several segments and find the answer on every segment, because the ternary search is incorrect in this problem.</p><p>The last two solutions can provide accepted, if you realize them carefully. Also note, that there is the solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>)</span> by the author <a class=\"rated-user user-orange\" href=\"/profile/RAD\" title=\"International Master RAD\">RAD</a>.</p><p><a href=\"/contest/266/problem/E\" title=\"Codeforces Round 163 (Div. 2)\">266E - More Queries to Array...</a></p><p>This problem can be solved using data structure. We would use segment tree, we will support <span class=\"tex-span\"><i>k</i></span> segment trees for every power. At every vertex we will calculate weighted sum of the appropriate power, also we will save some number that indicates the color of the whole segment, if any.</p><p>User <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> in comments to the post and user <a class=\"rated-user user-violet\" href=\"/profile/mexmans\" title=\"Candidate Master mexmans\">mexmans</a> in comments to the tutorial tell their formula to get the answer. I try to describe how to get them by yourself. Firstly, you should write what value your segment tree gives. The tree can calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a5b58e8b23c7841d1d63b86cb9dff69967de47a9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. You need to calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c643f7f8655fd5b92fece5daa272e472e6c8f830.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, you can write it also as <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6328f7eee132b5640555cc7d5315c4a3b3a21417.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then you should write the last sum for some first powers (at least three) (at piece of paper) and subtract the second sum (what you need) from the first sum (what your tree can calculate). You get an expression that describes what should be subtracted to get the answer from the value what you tree can calculate. This is just the Newton binomial without the highest power.</p><p>So, the answer for power <span class=\"tex-span\"><i>j</i></span> is expressed as the subtraction of the value of query to your segment tree and the Newton binomial, with all powers that are less than <span class=\"tex-span\"><i>j</i></span> (these values can also calculated using your segment tree). Partial sum of the powers and binomial coefficients can be precalced. The solution has the complexity <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>K</i>·<i>log</i>(<i>N</i>))</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/266\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 163 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-6546\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"6499\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=163\" class=\"tag notice\" style=\"text-decoration: none;\">163</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+21</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6499#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6499#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6556\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (44)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119720\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119720\" href=\"?#comment-119720\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119720\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119720\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for d & e?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119720 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119720 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119720\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119734\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ximera\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57168/avatar/5b9093f6cb7c97f6.jpg'/> </a>\n <div><a href=\"/profile/Ximera\" title=\"Master Ximera\" class=\"rated-user user-orange\">Ximera</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:59\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119734\" href=\"?#comment-119734\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119734\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"57168\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119734\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Bit patience my friend :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119734 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119734 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119734\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119742\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 19:27\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119742\" href=\"?#comment-119742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119742\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It has not been ready yet.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119742\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119748\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xeronix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8425/avatar/b652c95a2089a33b.jpg'/> </a>\n <div><a href=\"/profile/xeronix\" title=\"Expert xeronix\" class=\"rated-user user-blue\">xeronix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 20:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119748\" href=\"?#comment-119748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119748\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"8425\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For D i tried the following approach but somehow couldn't finish debugging it. </p> <pre><code>For all those vertices v whose eccentricity == radius of graph:\n For all the adjoining edges of v i.e. edge(v,x):\n Binary Search for the location l on the edge (v,x) which minimizes graph \n radius considering l as a vertex\n Keep track of minimum of all such graph radii\n</code></pre><p>Will it work ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119748\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119774\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119774\" href=\"?#comment-119774\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119774\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119774\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C the important part is how can you find the 0 row fast (I mean the row with all numbers 0 in it), because you do it O(N) times and naive way (O(N^2)) is not sufficient. I used some dynamic arrays and updated them after each swap. For me the difficulty was in implementation and not in the algorithm, I got it in about 5 minutes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119774 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119774 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119774\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119776\" commentParentId=\"119774\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guliashvili\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39591/avatar/37cde92b05e59c05.jpg'/> </a>\n <div><a href=\"/profile/guliashvili\" title=\"Candidate Master guliashvili\" class=\"rated-user user-violet\">guliashvili</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119776\" href=\"?#comment-119776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119774\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n = 1000 whats the problem with n^2 algo?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119776\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119787\" commentParentId=\"119776\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 23:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119787\" href=\"?#comment-119787\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119776\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119787\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119787\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>you do N^2 thing O(N) times, in total it becomes O(N^3). I mean in O(N) times you will have to find 0 row in remaining square. That's not a straightforward thing to do, for me it was harder than the part that is written in the tutorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119787 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119787 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119787\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119789\" commentParentId=\"119787\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119789\" href=\"?#comment-119789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119787\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>you have O(n) phases (O(n) swaps to make):\n each phase you search for the appropriate column //O(n)\n you perform the swap in O(n)\n</code></pre><p>the two steps are independent, so this gives O(n^2), which is feasible. you just need an array of size n counting the number of ones in each column to search for the appropriate column in O(n)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119789\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119791\" commentParentId=\"119789\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119791\" href=\"?#comment-119791\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119789\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119791\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119791\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>that's what I did actually</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119791 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119791 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119791\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119777\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119777\" href=\"?#comment-119777\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119777\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119777\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D and E ? at least some hint ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119777 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119777 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119777\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119850\" commentParentId=\"119777\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kraskevich\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41036/avatar/baa5690e761857ad.jpg'/> </a>\n <div><a href=\"/profile/kraskevich\" title=\"International Grandmaster kraskevich\" class=\"rated-user user-red\">kraskevich</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:18\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119850\" href=\"?#comment-119850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119777\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119850\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"41036\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>E: 1) Let's understand how to solve this problem if k for all queries to calculate the sum is equal to 0. It's quite easy to do it: we can just use a segment tree.</p><p>2) Let's learn to answer queries where k is greater than zero. Let's assume that we know a correct answer for a node's left child and right child. We need to merge node's children answers. To do it, we can figure out the following formula: answer for current node and power k ans[k] = ans_left[k] + ans_right[k] + sum for all 1 <= j <= k ans_right[k — j] * L ^ j * c[k][j], where ans_left and ans_right are the answers for node's children, c[k][j] is a binomial coefficient and L is the length of a segment represented by the left child of the node.</p><p>3) However, we still don't know how to process assign queries. But this is rather simple: if we precalculate prefix sums for all powers, we'll be able to find a value for a certain node in a tree in constant time even if its value has been updated.</p><p>Such solutuion works in O(N + M log N) time. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120420\" commentParentId=\"119850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 07:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120420\" href=\"?#comment-120420\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120420\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120420\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks for the hint</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120420 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120420 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120420\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119792\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kotenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44176/avatar/7983fd66b7982a73.jpg'/> </a>\n <div><a href=\"/profile/Kotenko\" title=\"Specialist Kotenko\" class=\"rated-user user-cyan\">Kotenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119792\" href=\"?#comment-119792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119792\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44176\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems that I had underestimated the C problem — very interesting idea to solve it.<br />Thanks for tutorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119792\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119793\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stifff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78162/avatar/af74a0645f71a854.jpg'/> </a>\n <div><a href=\"/profile/stifff\" title=\"Specialist stifff\" class=\"rated-user user-cyan\">stifff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119793\" href=\"?#comment-119793\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119793\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78162\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119793\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could I solve D Problem, using Hakimi algo, for searching an absolute center of Graph?</p><p>Article in Russian is here:</p><p><a href=\"http://www.uchimatchast.ru/teory/abs_center.php\">http://www.uchimatchast.ru/teory/abs_center.php</a></p><p>(algo in the bottom of the page)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119793 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119793 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119793\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119794\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/howsiwei\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/howsiwei\" title=\"Candidate Master howsiwei\" class=\"rated-user user-violet\">howsiwei</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 04:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119794\" href=\"?#comment-119794\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119794\" revisionCount=\"8\" revision=\"8\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">8</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119794\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77740\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119794\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem C there is an O(n) solution. <a href=\"/contest/266/submission/2997252\" title=\"Submission 2997252 by howsiwei\">2997252</a> (this is not my original idea, i learnt it from <a href=\"/contest/266/submission/2993213\" title=\"Submission 2993213 by tjsudys\">2993213</a> and edit the swap part to make it O(n)) The main idea is that after j steps, for all 1<k<=j, kth marked cell will lies in column 1 to k, row c+1(c=its column number) to j+1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119794 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119794 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119794\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119808\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:13\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119808\" href=\"?#comment-119808\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119808\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119808\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119808\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119808 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119808 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119808\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119809\" commentParentId=\"119808\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iensen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/iensen\" title=\"Candidate Master iensen\" class=\"rated-user user-violet\">iensen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119809\" href=\"?#comment-119809\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119808\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119809\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"504\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119809\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You are right that two swaps are needed, but by <a href=\"https://en.wikipedia.org/wiki/Big_O_notation\">definition of Big-O notation</a>, there is no difference between O(N) and O(2*N). O(N) means there is some fixed constant M such that algorithm works in time M*N for each input of any size N. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119809 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119809 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119809\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119813\" commentParentId=\"119809\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 12:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119813\" href=\"?#comment-119813\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119809\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119813\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119813\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119813\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119813 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119813 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119813\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119821\" commentParentId=\"119813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ramint\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/74825/avatar/8a16585522c3dce2.jpg'/> </a>\n <div><a href=\"/profile/ramint\" title=\"Newbie ramint\" class=\"rated-user user-gray\">ramint</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119821\" href=\"?#comment-119821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"74825\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>but it doesnt mean ,your swaps take o(2*n) ......</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119821\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119822\" commentParentId=\"119821\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119822\" href=\"?#comment-119822\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119821\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119822\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119822\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119822\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119822 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119822 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119822\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119811\" href=\"?#comment-119811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Tutorial for chinese version <a href=\"http://blog.csdn.net/haha593572013/article/details/8538216\">chick here</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119811\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119840\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 17:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119840\" href=\"?#comment-119840\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119840\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119840\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My idea for problem D is using ford-bellman, then with every edge[i], I find the furthest way from edge[i].x, from edge[i].y without pass through the edge[i] and determine the point, but I get WA. Anyone can explain, or have a wrong test case for that ? Thank you for helping, and sorry for my poor english :).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119840 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119840 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119840\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119845\" commentParentId=\"119840\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 18:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119845\" href=\"?#comment-119845\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119840\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119845\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119845\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>open your submission, you'll find the test cases below your code, and you'll find the one that gives your WA.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119845 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119845 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119845\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119848\" commentParentId=\"119845\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119848\" href=\"?#comment-119848\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119845\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119848\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119848\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know about that, but that one is too big.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119848 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119848 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119848\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119854\" commentParentId=\"119848\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119854\" href=\"?#comment-119854\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119848\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119854\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119854\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119854\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How do you determinate the point on edge? You can't use ternary search, because function on it isn't convex</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119854 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119854 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119854\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119856\" commentParentId=\"119854\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119856\" href=\"?#comment-119856\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119854\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119856\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119856\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>point = ( furthest(edge[i].x) — furthest(edge[i].y) + edge[i].w )/2; Is it right ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119856 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119856 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119856\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119861\" commentParentId=\"119856\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:43\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119861\" href=\"?#comment-119861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119856\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, it isn't. I thought so too, but <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> said me, that function on the edge is piece-wise linear. So you must disintegrate it on the segments. I'm still thinking, how to do it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120017\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:37\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120017\" href=\"?#comment-120017\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120017\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120017\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a Monotonicity when the answer(ans) is increasing , you will find more such points that satisfy the condition Max_shortest_distance <= ans,so i think you can try binary search of this problem .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120017 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120017 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120017\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120171\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 14:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120171\" href=\"?#comment-120171\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120171\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120171\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have you passed the solution? If yes, please write the idea :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120171 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120171 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120171\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120000\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21339/avatar/58866417a0c9f963.jpg'/> </a>\n <div><a href=\"/profile/irakli\" title=\"Specialist irakli\" class=\"rated-user user-cyan\">irakli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2013 22:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120000\" href=\"?#comment-120000\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120000\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"36\"\r\n data-commentUserId=\"21339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+36</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120000\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Still waiting for D and E solutions...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120000 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120000 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120000\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120016\" commentParentId=\"120000\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mosiomohsen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42052/avatar/5d107e4760b3f346.jpg'/> </a>\n <div><a href=\"/profile/mosiomohsen\" title=\"Specialist mosiomohsen\" class=\"rated-user user-cyan\">mosiomohsen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120016\" href=\"?#comment-120016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120000\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"42052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>:-w</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120016\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120042\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/vinaybajaj2610\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25881/avatar/4c912eb678ab859d.jpg'/> </a>\n <div><a href=\"/profile/vinaybajaj2610\" title=\"Expert vinaybajaj2610\" class=\"rated-user user-blue\">vinaybajaj2610</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 15:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120042\" href=\"?#comment-120042\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120042\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"25881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120042\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you also should provide the link to good code for each problem in contest with each problems explanation in tutorial. [ Best : Good and nice implementation and better complexity]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120042 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120042 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120042\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120059\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tjsumonster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82432/avatar/dfcbf8967ac2147c.jpg'/> </a>\n <div><a href=\"/profile/tjsumonster\" title=\"Expert tjsumonster\" class=\"rated-user user-blue\">tjsumonster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 16:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120059\" href=\"?#comment-120059\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120059\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"82432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120059\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for D & E pls!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120059 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120059 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120059\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120223\" commentParentId=\"120059\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tctony\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3000/avatar/c90abcf148ccb4c.jpg'/> </a>\n <div><a href=\"/profile/tctony\" title=\"Specialist tctony\" class=\"rated-user user-cyan\">tctony</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 08:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120223\" href=\"?#comment-120223\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120059\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120223\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"3000\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120223\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find editorial for D from problem C at <a href=\"http://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">here</a>.</p><p>Hope someone can do some explanation on E!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120223 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120223 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120223\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120275\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 19:03\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120275\" href=\"?#comment-120275\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120275\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120275\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks, nice explanation of problem D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120275 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120275 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120275\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121286\" commentParentId=\"120275\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 00:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121286\" href=\"?#comment-121286\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120275\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121286\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121286\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry but I don't think so: In the discussion of D we read: " It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations." I don't think that it is true for the 3-rd example. Even if not so, the proof is quite ambiguous. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121286 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121286 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121286\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120429\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120429\" href=\"?#comment-120429\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120429\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120429\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>whats that?</p><p>there are only solutions. where to read problems ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120429 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120429 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120429\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121254\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2013 17:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121254\" href=\"?#comment-121254\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121254\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121254\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121254\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121254 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121254 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121254\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"547929\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2019 20:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-547929\" href=\"?#comment-547929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"547929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-547929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great source for learning the Min. Diameter Spanning Tree but the link seems to be broken. Here's the web archive link for the pdf: <a href=\"https://web.archive.org/web/20160309101249/https://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">Link</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-547929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-547929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-547929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120230\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/husseincoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/5219/avatar/de8f1c32ce880839.jpg'/> </a>\n <div><a href=\"/profile/husseincoder\" title=\"Specialist husseincoder\" class=\"rated-user user-cyan\">husseincoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 14:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120230\" href=\"?#comment-120230\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120230\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5219\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120230\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my approach that gets WA.. but i don't know why..</p><p>First i compute the shortest distance between pairs using floyd warshal, then iterate all pairs getting the furthest node to each one of them.. then using binary search i get the optimal place on the road of those pair.. getting the min for every pair and printing it.</p><p>Can anybody tell me whats the problem of my solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120230 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120230 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120230\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"373902\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CaptainRubik_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/343348/avatar/19c785dbaef44419.jpg'/> </a>\n <div><a href=\"/profile/CaptainRubik_\" title=\"Pupil CaptainRubik_\" class=\"rated-user user-green\">CaptainRubik_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2017 05:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-373902\" href=\"?#comment-373902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"373902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"343348\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-373902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The tags for Div2B include Max flow. Can anyone elaborate on how to model this problem as a graph?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-373902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-373902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-373902\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"943288\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coder_firegun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1825864/avatar/c03899f54d682484.jpg'/> </a>\n <div><a href=\"/profile/coder_firegun\" title=\"Pupil coder_firegun\" class=\"rated-user user-green\">coder_firegun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/15/2022 11:23\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-943288\" href=\"?#comment-943288\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"943288\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1825864\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-943288\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve problem B when constraints are large using graphs as mentioned in problem tags</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-943288 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-943288 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-943288\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966578\" commentParentId=\"943288\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/diwaseharsh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/diwaseharsh\" title=\"Newbie diwaseharsh\" class=\"rated-user user-gray\">diwaseharsh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 10:24\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966578\" href=\"?#comment-966578\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-943288\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966578\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2517510\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966578\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also wanna know. but i dont know maps ...</p><p>can U share ur code??????</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966578 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966578 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966578\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1027114\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepaksolution\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/deepaksolution\" title=\"Unrated, deepaksolution\" class=\"rated-user user-black\">deepaksolution</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/03/2023 20:15\">5 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1027114\" href=\"?#comment-1027114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1027114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3184366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1027114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Solution of 266B — Queue at the School Is Here in the below link with explanation of code</strong></p><p><a href=\"https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html\">https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply 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More Queries to Array..."},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. More Queries to Array...</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You've got an array, consisting of <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>. Your task is to quickly run the queries of two types:</p><ol><li> Assign value <span class=\"tex-span\"><i>x</i></span> to all elements from <span class=\"tex-span\"><i>l</i></span> to <span class=\"tex-span\"><i>r</i></span> inclusive. After such query the values of the elements of array <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>l</i></sub>, <i>a</i><sub class=\"lower-index\"><i>l</i> + 1</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>r</i></sub></span> become equal to <span class=\"tex-span\"><i>x</i></span>.</li><li> Calculate and print sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/920d5e77b57e41992ceefa42465edf8cfc006a39.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>, where <span class=\"tex-span\"><i>k</i></span> doesn't exceed <span class=\"tex-span\">5</span>. As the value of the sum can be rather large, you should print it modulo <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>), showing, how many numbers are in the array and the number of queries, correspondingly. The second line contains <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>) — the initial values of the array elements.</p><p>Then <span class=\"tex-span\"><i>m</i></span> queries follow, one per line:</p><ol><li> The assign query has the following format: \"<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b2ef693fd11e9e29c50f180848ea668ed6d33b22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>\", (<span class=\"tex-span\">1 ≤ <i>l</i> ≤ <i>r</i> ≤ <i>n</i>; 0 ≤ <i>x</i> ≤ 10<sup class=\"upper-index\">9</sup></span>).</li><li> The query to calculate the sum has the following format: \"<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6a63948f42b361ef379406ad9a679d1da1aee76b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>\", (<span class=\"tex-span\">1 ≤ <i>l</i> ≤ <i>r</i> ≤ <i>n</i>; 0 ≤ <i>k</i> ≤ 5</span>).</li></ol><p>All numbers in the input are integers.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query to calculate the sum print an integer — the required sum modulo <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br/>5 10 2 1<br/>? 1 2 1<br/>= 2 2 0<br/>? 2 4 3<br/>= 1 4 1<br/>? 1 4 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>25<br/>43<br/>1300<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 1<br/>1000000000 1000000000 1000000000<br/>? 1 3 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>999999986<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"720937f06c64af24628f72acf81a7e58\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e5bd61caad7ef105f73513b491ec03004e7de55a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/266\">Codeforces Round 163 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/266/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n 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data-uuid=\"ps_b2ba2f5196f8f20339b7d8c3f2a5ccaf5f4d7f0b\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. More Queries to Array...</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You've got an array, consisting of <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>. Your task is to quickly run the queries of two types:</p><ol><li> Assign value <span class=\"tex-span\"><i>x</i></span> to all elements from <span class=\"tex-span\"><i>l</i></span> to <span class=\"tex-span\"><i>r</i></span> inclusive. After such query the values of the elements of array <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>l</i></sub>, <i>a</i><sub class=\"lower-index\"><i>l</i> + 1</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>r</i></sub></span> become equal to <span class=\"tex-span\"><i>x</i></span>.</li><li> Calculate and print sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/920d5e77b57e41992ceefa42465edf8cfc006a39.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, where <span class=\"tex-span\"><i>k</i></span> doesn't exceed <span class=\"tex-span\">5</span>. As the value of the sum can be rather large, you should print it modulo <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>), showing, how many numbers are in the array and the number of queries, correspondingly. The second line contains <span class=\"tex-span\"><i>n</i></span> integers: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>) — the initial values of the array elements.</p><p>Then <span class=\"tex-span\"><i>m</i></span> queries follow, one per line:</p><ol><li> The assign query has the following format: "<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b2ef693fd11e9e29c50f180848ea668ed6d33b22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />", (<span class=\"tex-span\">1 ≤ <i>l</i> ≤ <i>r</i> ≤ <i>n</i>; 0 ≤ <i>x</i> ≤ 10<sup class=\"upper-index\">9</sup></span>).</li><li> The query to calculate the sum has the following format: "<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6a63948f42b361ef379406ad9a679d1da1aee76b.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />", (<span class=\"tex-span\">1 ≤ <i>l</i> ≤ <i>r</i> ≤ <i>n</i>; 0 ≤ <i>k</i> ≤ 5</span>).</li></ol><p>All numbers in the input are integers.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each query to calculate the sum print an integer — the required sum modulo <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br />5 10 2 1<br />? 1 2 1<br />= 2 2 0<br />? 2 4 3<br />= 1 4 1<br />? 1 4 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>25<br />43<br />1300<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 1<br />1000000000 1000000000 1000000000<br />? 1 3 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>999999986<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='6a738ad05acb379636bd06c9a5923677'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/HolkinPV\">HolkinPV</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/HolkinPV\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/HolkinPV\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/HolkinPV\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/HolkinPV\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/HolkinPV\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/HolkinPV\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/HolkinPV\" style=\"text-decoration:none;color:black !important;\">HolkinPV's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6546\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6499\"> <p>Codeforces Round #163 (Div. 2) Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/HolkinPV\" title=\"Candidate Master HolkinPV\" class=\"rated-user user-violet\">HolkinPV</a>,\r\n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/266/problem/A\" title=\"Codeforces Round 163 (Div. 2)\">266A - Stones on the Table</a></p><p>In this problem you should count number of consecutive pairs of equal letters. It can be done using one cycle and <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> time.</p><p><a href=\"/contest/266/problem/B\" title=\"Codeforces Round 163 (Div. 2)\">266B - Queue at the School</a></p><p>In this you should realize the given process. You should <span class=\"tex-span\"><i>t</i></span> times swap elements <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i> + 1</span> if on the place <span class=\"tex-span\"><i>i</i></span> was a girl and on the place <span class=\"tex-span\"><i>i</i> + 1</span> was a boy. You should not push some girl to the left multiple times at once. The solution can be written using <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>T</i>)</span> time. </p><p><a href=\"/contest/266/problem/C\" title=\"Codeforces Round 163 (Div. 2)\">266C - Below the Diagonal</a></p><p>This problem can be solved using constructive algorithm. We will use inductive approach. At first, we have matrix of size <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>n</i> - 1</span> ones in it. Therefore, there is a column with no ones in it. So, we put this column to <span class=\"tex-span\"><i>n</i></span>-th place. In this case, the lower right element will be <span class=\"tex-span\">0</span>. Then find any row with at least one integer one and put it to the <span class=\"tex-span\"><i>n</i></span>-th place.</p><p>After these operations the element in cell <span class=\"tex-span\">(<i>n</i>, <i>n</i>)</span> equals to <span class=\"tex-span\">0</span> and the last row has at least one integer one. Therefore, we can reduce the dimension of our problem, that is <span class=\"tex-span\"><i>n</i>: = <i>n</i> - 1</span>. In our new problem we have no more than <span class=\"tex-span\"><i>n</i> - 2</span> ones. So, we can solve this problem using the same algorithm. When <span class=\"tex-span\"><i>n</i></span> equals to <span class=\"tex-span\">1</span> you should finish algorithm, because there is no ones left. This algorithm uses <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span> swap operations, no more than two for every <span class=\"tex-span\"><i>n</i></span>.</p><p><a href=\"/contest/266/problem/D\" title=\"Codeforces Round 163 (Div. 2)\">266D - BerDonalds</a></p><p>I'll tell a few ideas how to solve this problem. Firstly, describe the solution with time <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span>. Consider every edge <span class=\"tex-span\">(<i>u</i>, <i>v</i>)</span> of length <span class=\"tex-span\"><i>len</i></span> where could be the answer point. Let this point lie at a distance <span class=\"tex-span\"><i>x</i></span> from vertex <span class=\"tex-span\"><i>u</i></span>. So, the distance from this point to vertex <span class=\"tex-span\"><i>i</i></span> would be <span class=\"tex-span\"><i>min</i>(<i>x</i> + <i>d</i>[<i>u</i>][<i>i</i>], <i>len</i>–<i>x</i> + <i>d</i>[<i>v</i>][<i>i</i>])</span>, where <span class=\"tex-span\"><i>d</i>[<i>x</i>][<i>y</i>]</span> — distance between vertices <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span>. Equate these values and get the critical value <span class=\"tex-span\"><i>x</i></span> for vertex <span class=\"tex-span\"><i>i</i></span>, <span class=\"tex-span\"><i>x</i> = (<i>len</i> + <i>d</i>[<i>v</i>][<i>i</i>]–<i>d</i>[<i>u</i>][<i>i</i>]) / 2</span>. It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations.</p><p>Another solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>·<i>log</i><sup class=\"upper-index\">2</sup>)</span>. Multiply all weights by <span class=\"tex-span\">2</span>. Consider every edge where should be the answer and make binary search for the answer (in integers). To check some current value you should consider every vertex <span class=\"tex-span\"><i>i</i></span> and assume that the answer is achieved in this vertex. In this case, the answer point must lie on this edge <= some value <span class=\"tex-span\"><i>l</i>[<i>i</i>]</span> or >= some value <span class=\"tex-span\"><i>r</i>[<i>i</i>]</span>. This subproblem is solved using offline algorithm using sorting events and maintaining the balance.</p><p>Also, you can use ternary search on every edge of the graph. But you should divide every edge on several segments and find the answer on every segment, because the ternary search is incorrect in this problem.</p><p>The last two solutions can provide accepted, if you realize them carefully. Also note, that there is the solution with complexity <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">3</sup>)</span> by the author <a class=\"rated-user user-orange\" href=\"/profile/RAD\" title=\"International Master RAD\">RAD</a>.</p><p><a href=\"/contest/266/problem/E\" title=\"Codeforces Round 163 (Div. 2)\">266E - More Queries to Array...</a></p><p>This problem can be solved using data structure. We would use segment tree, we will support <span class=\"tex-span\"><i>k</i></span> segment trees for every power. At every vertex we will calculate weighted sum of the appropriate power, also we will save some number that indicates the color of the whole segment, if any.</p><p>User <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> in comments to the post and user <a class=\"rated-user user-violet\" href=\"/profile/mexmans\" title=\"Candidate Master mexmans\">mexmans</a> in comments to the tutorial tell their formula to get the answer. I try to describe how to get them by yourself. Firstly, you should write what value your segment tree gives. The tree can calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a5b58e8b23c7841d1d63b86cb9dff69967de47a9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. You need to calculate the sum <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c643f7f8655fd5b92fece5daa272e472e6c8f830.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, you can write it also as <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/6328f7eee132b5640555cc7d5315c4a3b3a21417.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Then you should write the last sum for some first powers (at least three) (at piece of paper) and subtract the second sum (what you need) from the first sum (what your tree can calculate). You get an expression that describes what should be subtracted to get the answer from the value what you tree can calculate. This is just the Newton binomial without the highest power.</p><p>So, the answer for power <span class=\"tex-span\"><i>j</i></span> is expressed as the subtraction of the value of query to your segment tree and the Newton binomial, with all powers that are less than <span class=\"tex-span\"><i>j</i></span> (these values can also calculated using your segment tree). Partial sum of the powers and binomial coefficients can be precalced. The solution has the complexity <span class=\"tex-span\"><i>O</i>(<i>N</i>·<i>K</i>·<i>log</i>(<i>N</i>))</span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/266\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 163 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230-6546\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230\",\n blogEntryId: \"6499\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=163\" class=\"tag notice\" style=\"text-decoration: none;\">163</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+21</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6546\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/HolkinPV\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/HolkinPV\">\n HolkinPV\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jan/23/2013 17:06\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6499#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6499#comments\">\n 52\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6556\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (44)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119720\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karan173\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/karan173\" title=\"Expert karan173\" class=\"rated-user user-blue\">karan173</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119720\" href=\"?#comment-119720\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119720\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"11\"\r\n data-commentUserId=\"53106\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+11</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119720\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for d & e?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119720 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119720 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119720\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119734\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Ximera\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57168/avatar/5b9093f6cb7c97f6.jpg'/> </a>\n <div><a href=\"/profile/Ximera\" title=\"Master Ximera\" class=\"rated-user user-orange\">Ximera</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 18:59\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119734\" href=\"?#comment-119734\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119734\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"57168\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119734\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Bit patience my friend :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119734 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119734 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119734\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119742\" commentParentId=\"119720\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 19:27\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119742\" href=\"?#comment-119742\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119720\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119742\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119742\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119742\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It has not been ready yet.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119742 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119742 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119742\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119748\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/xeronix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/8425/avatar/b652c95a2089a33b.jpg'/> </a>\n <div><a href=\"/profile/xeronix\" title=\"Expert xeronix\" class=\"rated-user user-blue\">xeronix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 20:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119748\" href=\"?#comment-119748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119748\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"8425\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For D i tried the following approach but somehow couldn't finish debugging it. </p> <pre><code>For all those vertices v whose eccentricity == radius of graph:\n For all the adjoining edges of v i.e. edge(v,x):\n Binary Search for the location l on the edge (v,x) which minimizes graph \n radius considering l as a vertex\n Keep track of minimum of all such graph radii\n</code></pre><p>Will it work ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119748\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119774\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119774\" href=\"?#comment-119774\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119774\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119774\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In problem C the important part is how can you find the 0 row fast (I mean the row with all numbers 0 in it), because you do it O(N) times and naive way (O(N^2)) is not sufficient. I used some dynamic arrays and updated them after each swap. For me the difficulty was in implementation and not in the algorithm, I got it in about 5 minutes.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119774 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119774 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119774\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119776\" commentParentId=\"119774\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guliashvili\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/39591/avatar/37cde92b05e59c05.jpg'/> </a>\n <div><a href=\"/profile/guliashvili\" title=\"Candidate Master guliashvili\" class=\"rated-user user-violet\">guliashvili</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119776\" href=\"?#comment-119776\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119774\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119776\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"39591\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119776\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>n = 1000 whats the problem with n^2 algo?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119776 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119776 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119776\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119787\" commentParentId=\"119776\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 23:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119787\" href=\"?#comment-119787\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119776\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119787\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119787\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>you do N^2 thing O(N) times, in total it becomes O(N^3). I mean in O(N) times you will have to find 0 row in remaining square. That's not a straightforward thing to do, for me it was harder than the part that is written in the tutorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119787 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119787 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119787\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119789\" commentParentId=\"119787\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119789\" href=\"?#comment-119789\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119787\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119789\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119789\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><pre><code>you have O(n) phases (O(n) swaps to make):\n each phase you search for the appropriate column //O(n)\n you perform the swap in O(n)\n</code></pre><p>the two steps are independent, so this gives O(n^2), which is feasible. you just need an array of size n counting the number of ones in each column to search for the appropriate column in O(n)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119789 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119789 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119789\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119791\" commentParentId=\"119789\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 00:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119791\" href=\"?#comment-119791\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119789\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119791\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119791\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>that's what I did actually</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119791 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119791 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119791\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119777\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119777\" href=\"?#comment-119777\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119777\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119777\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D and E ? at least some hint ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119777 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119777 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119777\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119850\" commentParentId=\"119777\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kraskevich\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/41036/avatar/baa5690e761857ad.jpg'/> </a>\n <div><a href=\"/profile/kraskevich\" title=\"International Grandmaster kraskevich\" class=\"rated-user user-red\">kraskevich</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:18\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119850\" href=\"?#comment-119850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119777\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119850\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"10\"\r\n data-commentUserId=\"41036\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>E: 1) Let's understand how to solve this problem if k for all queries to calculate the sum is equal to 0. It's quite easy to do it: we can just use a segment tree.</p><p>2) Let's learn to answer queries where k is greater than zero. Let's assume that we know a correct answer for a node's left child and right child. We need to merge node's children answers. To do it, we can figure out the following formula: answer for current node and power k ans[k] = ans_left[k] + ans_right[k] + sum for all 1 <= j <= k ans_right[k — j] * L ^ j * c[k][j], where ans_left and ans_right are the answers for node's children, c[k][j] is a binomial coefficient and L is the length of a segment represented by the left child of the node.</p><p>3) However, we still don't know how to process assign queries. But this is rather simple: if we precalculate prefix sums for all powers, we'll be able to find a value for a certain node in a tree in constant time even if its value has been updated.</p><p>Such solutuion works in O(N + M log N) time. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120420\" commentParentId=\"119850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 07:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120420\" href=\"?#comment-120420\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120420\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120420\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks for the hint</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120420 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120420 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120420\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119792\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kotenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44176/avatar/7983fd66b7982a73.jpg'/> </a>\n <div><a href=\"/profile/Kotenko\" title=\"Specialist Kotenko\" class=\"rated-user user-cyan\">Kotenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119792\" href=\"?#comment-119792\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119792\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119792\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44176\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119792\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems that I had underestimated the C problem — very interesting idea to solve it.<br />Thanks for tutorial!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119792 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119792 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119792\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119793\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/stifff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/78162/avatar/af74a0645f71a854.jpg'/> </a>\n <div><a href=\"/profile/stifff\" title=\"Specialist stifff\" class=\"rated-user user-cyan\">stifff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 01:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119793\" href=\"?#comment-119793\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119793\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78162\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119793\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could I solve D Problem, using Hakimi algo, for searching an absolute center of Graph?</p><p>Article in Russian is here:</p><p><a href=\"http://www.uchimatchast.ru/teory/abs_center.php\">http://www.uchimatchast.ru/teory/abs_center.php</a></p><p>(algo in the bottom of the page)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119793 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119793 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119793\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119794\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/howsiwei\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/howsiwei\" title=\"Candidate Master howsiwei\" class=\"rated-user user-violet\">howsiwei</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 04:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119794\" href=\"?#comment-119794\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119794\" revisionCount=\"8\" revision=\"8\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">8</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119794\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77740\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119794\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem C there is an O(n) solution. <a href=\"/contest/266/submission/2997252\" title=\"Submission 2997252 by howsiwei\">2997252</a> (this is not my original idea, i learnt it from <a href=\"/contest/266/submission/2993213\" title=\"Submission 2993213 by tjsudys\">2993213</a> and edit the swap part to make it O(n)) The main idea is that after j steps, for all 1<k<=j, kth marked cell will lies in column 1 to k, row c+1(c=its column number) to j+1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119794 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119794 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119794\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119808\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:13\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119808\" href=\"?#comment-119808\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119808\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119808\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119808\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119808 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119808 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119808\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119809\" commentParentId=\"119808\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/iensen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/iensen\" title=\"Candidate Master iensen\" class=\"rated-user user-violet\">iensen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119809\" href=\"?#comment-119809\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119808\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119809\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"504\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119809\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You are right that two swaps are needed, but by <a href=\"https://en.wikipedia.org/wiki/Big_O_notation\">definition of Big-O notation</a>, there is no difference between O(N) and O(2*N). O(N) means there is some fixed constant M such that algorithm works in time M*N for each input of any size N. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119809 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119809 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119809\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119813\" commentParentId=\"119809\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 12:00\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119813\" href=\"?#comment-119813\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119809\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119813\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119813\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119813\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119813 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119813 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119813\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119821\" commentParentId=\"119813\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ramint\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/74825/avatar/8a16585522c3dce2.jpg'/> </a>\n <div><a href=\"/profile/ramint\" title=\"Newbie ramint\" class=\"rated-user user-gray\">ramint</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119821\" href=\"?#comment-119821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119813\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"74825\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>but it doesnt mean ,your swaps take o(2*n) ......</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119821\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119822\" commentParentId=\"119821\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 14:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119822\" href=\"?#comment-119822\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119821\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119822\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119822\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119822\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119822 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119822 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119822\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119811\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 11:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119811\" href=\"?#comment-119811\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119811\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119811\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Tutorial for chinese version <a href=\"http://blog.csdn.net/haha593572013/article/details/8538216\">chick here</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119811 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119811 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119811\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119840\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 17:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119840\" href=\"?#comment-119840\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119840\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119840\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>My idea for problem D is using ford-bellman, then with every edge[i], I find the furthest way from edge[i].x, from edge[i].y without pass through the edge[i] and determine the point, but I get WA. Anyone can explain, or have a wrong test case for that ? Thank you for helping, and sorry for my poor english :).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119840 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119840 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119840\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119845\" commentParentId=\"119840\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LifeMaker\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/LifeMaker\" title=\"Expert LifeMaker\" class=\"rated-user user-blue\">LifeMaker</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 18:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119845\" href=\"?#comment-119845\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119840\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119845\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119845\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>open your submission, you'll find the test cases below your code, and you'll find the one that gives your WA.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119845 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119845 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119845\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119848\" commentParentId=\"119845\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119848\" href=\"?#comment-119848\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119845\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119848\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119848\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I know about that, but that one is too big.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119848 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119848 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119848\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119854\" commentParentId=\"119848\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119854\" href=\"?#comment-119854\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119848\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"119854\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"119854\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119854\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How do you determinate the point on edge? You can't use ternary search, because function on it isn't convex</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119854 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119854 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119854\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119856\" commentParentId=\"119854\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/doanminhdragon\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/58214/avatar/c6a7afb9ca95118d.jpg'/> </a>\n <div><a href=\"/profile/doanminhdragon\" title=\"Expert doanminhdragon\" class=\"rated-user user-blue\">doanminhdragon</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119856\" href=\"?#comment-119856\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119854\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119856\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"58214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119856\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>point = ( furthest(edge[i].x) — furthest(edge[i].y) + edge[i].w )/2; Is it right ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119856 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119856 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119856\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119861\" commentParentId=\"119856\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/WiBk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/WiBk\" title=\"Expert WiBk\" class=\"rated-user user-blue\">WiBk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2013 20:43\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119861\" href=\"?#comment-119861\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119856\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119861\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"42652\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119861\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>No, it isn't. I thought so too, but <a class=\"rated-user user-red\" href=\"/profile/Egor\" title=\"International Grandmaster Egor\">Egor</a> said me, that function on the edge is piece-wise linear. So you must disintegrate it on the segments. I'm still thinking, how to do it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119861 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119861 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119861\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120017\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/problem-solved\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/51757/avatar/49ced212f3fcff97.jpg'/> </a>\n <div><a href=\"/profile/problem-solved\" title=\"Master problem-solved\" class=\"rated-user user-orange\">problem-solved</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:37\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120017\" href=\"?#comment-120017\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120017\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"51757\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120017\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>there is a Monotonicity when the answer(ans) is increasing , you will find more such points that satisfy the condition Max_shortest_distance <= ans,so i think you can try binary search of this problem .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120017 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120017 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120017\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120171\" commentParentId=\"119861\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/27/2013 14:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120171\" href=\"?#comment-120171\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119861\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120171\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120171\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Have you passed the solution? If yes, please write the idea :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120171 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120171 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120171\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120000\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/irakli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/21339/avatar/58866417a0c9f963.jpg'/> </a>\n <div><a href=\"/profile/irakli\" title=\"Specialist irakli\" class=\"rated-user user-cyan\">irakli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/25/2013 22:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120000\" href=\"?#comment-120000\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120000\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"36\"\r\n data-commentUserId=\"21339\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+36</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120000\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Still waiting for D and E solutions...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120000 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120000 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120000\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120016\" commentParentId=\"120000\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/mosiomohsen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42052/avatar/5d107e4760b3f346.jpg'/> </a>\n <div><a href=\"/profile/mosiomohsen\" title=\"Specialist mosiomohsen\" class=\"rated-user user-cyan\">mosiomohsen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 06:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120016\" href=\"?#comment-120016\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120000\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120016\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"42052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120016\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>:-w</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120016 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120016 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120016\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120042\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/vinaybajaj2610\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25881/avatar/4c912eb678ab859d.jpg'/> </a>\n <div><a href=\"/profile/vinaybajaj2610\" title=\"Expert vinaybajaj2610\" class=\"rated-user user-blue\">vinaybajaj2610</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 15:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120042\" href=\"?#comment-120042\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120042\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"25881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120042\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you also should provide the link to good code for each problem in contest with each problems explanation in tutorial. [ Best : Good and nice implementation and better complexity]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120042 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120042 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120042\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120059\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tjsumonster\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/82432/avatar/dfcbf8967ac2147c.jpg'/> </a>\n <div><a href=\"/profile/tjsumonster\" title=\"Expert tjsumonster\" class=\"rated-user user-blue\">tjsumonster</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/26/2013 16:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120059\" href=\"?#comment-120059\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120059\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"82432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120059\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>tutorials for D & E pls!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120059 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120059 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120059\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120223\" commentParentId=\"120059\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/tctony\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3000/avatar/c90abcf148ccb4c.jpg'/> </a>\n <div><a href=\"/profile/tctony\" title=\"Specialist tctony\" class=\"rated-user user-cyan\">tctony</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 08:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120223\" href=\"?#comment-120223\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120059\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120223\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"3000\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120223\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find editorial for D from problem C at <a href=\"http://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">here</a>.</p><p>Hope someone can do some explanation on E!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120223 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120223 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120223\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120275\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hbibnzamNipa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hbibnzamNipa\" title=\"Expert hbibnzamNipa\" class=\"rated-user user-blue\">hbibnzamNipa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 19:03\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120275\" href=\"?#comment-120275\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120275\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"82733\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120275\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks, nice explanation of problem D</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120275 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120275 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120275\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121286\" commentParentId=\"120275\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/llaki\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/24382/avatar/6683eebf7eea08ec.jpg'/> </a>\n <div><a href=\"/profile/llaki\" title=\"Expert llaki\" class=\"rated-user user-blue\">llaki</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 00:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121286\" href=\"?#comment-121286\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120275\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121286\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"24382\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121286\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry but I don't think so: In the discussion of D we read: " It follows that the answer to the problem is half-integer. So, for every edge and every other vertex we get set of critical points. We should check them all include the vertices of the graph (ends of the segments). This solution may probably pass with some optimizations." I don't think that it is true for the 3-rd example. Even if not so, the proof is quite ambiguous. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121286 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121286 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121286\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120429\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/29/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120429\" href=\"?#comment-120429\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120429\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120429\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>whats that?</p><p>there are only solutions. where to read problems ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120429 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120429 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120429\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121254\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Logarithmic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/62214/avatar/85ffb6cf9456a891.jpg'/> </a>\n <div><a href=\"/profile/Logarithmic\" title=\"Specialist Logarithmic\" class=\"rated-user user-cyan\">Logarithmic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/06/2013 17:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121254\" href=\"?#comment-121254\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121254\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121254\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"62214\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121254\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>a</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121254 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121254 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121254\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"547929\" commentParentId=\"120223\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/05/2019 20:03\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-547929\" href=\"?#comment-547929\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120223\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"547929\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-547929\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Great source for learning the Min. Diameter Spanning Tree but the link seems to be broken. Here's the web archive link for the pdf: <a href=\"https://web.archive.org/web/20160309101249/https://adn.botao.hu/adn-backup/blog/attachments/month_0705/32007531153238.pdf\">Link</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-547929 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-547929 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-547929\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120230\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/husseincoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/5219/avatar/de8f1c32ce880839.jpg'/> </a>\n <div><a href=\"/profile/husseincoder\" title=\"Specialist husseincoder\" class=\"rated-user user-cyan\">husseincoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/28/2013 14:17\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120230\" href=\"?#comment-120230\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120230\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5219\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120230\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Here is my approach that gets WA.. but i don't know why..</p><p>First i compute the shortest distance between pairs using floyd warshal, then iterate all pairs getting the furthest node to each one of them.. then using binary search i get the optimal place on the road of those pair.. getting the min for every pair and printing it.</p><p>Can anybody tell me whats the problem of my solution?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120230 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120230 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120230\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"373902\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/CaptainRubik_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/343348/avatar/19c785dbaef44419.jpg'/> </a>\n <div><a href=\"/profile/CaptainRubik_\" title=\"Pupil CaptainRubik_\" class=\"rated-user user-green\">CaptainRubik_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/18/2017 05:40\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-373902\" href=\"?#comment-373902\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"373902\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"343348\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-373902\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>The tags for Div2B include Max flow. Can anyone elaborate on how to model this problem as a graph?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-373902 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-373902 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-373902\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"943288\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/coder_firegun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1825864/avatar/c03899f54d682484.jpg'/> </a>\n <div><a href=\"/profile/coder_firegun\" title=\"Pupil coder_firegun\" class=\"rated-user user-green\">coder_firegun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Aug/15/2022 11:23\">14 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-943288\" href=\"?#comment-943288\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"943288\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1825864\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-943288\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How to solve problem B when constraints are large using graphs as mentioned in problem tags</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-943288 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-943288 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-943288\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"966578\" commentParentId=\"943288\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/diwaseharsh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/diwaseharsh\" title=\"Newbie diwaseharsh\" class=\"rated-user user-gray\">diwaseharsh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/23/2022 10:24\">12 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-966578\" href=\"?#comment-966578\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-943288\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"966578\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2517510\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-966578\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I also wanna know. but i dont know maps ...</p><p>can U share ur code??????</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-966578 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-966578 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-966578\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1027114\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepaksolution\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/deepaksolution\" title=\"Unrated, deepaksolution\" class=\"rated-user user-black\">deepaksolution</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/03/2023 20:15\">5 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1027114\" href=\"?#comment-1027114\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1027114\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3184366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1027114\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Solution of 266B — Queue at the School Is Here in the below link with explanation of code</strong></p><p><a href=\"https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html\">https://codeforcer.blogspot.com/2023/05/266b-queue-at-school-cpp-solution.html</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply 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Subtractions"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Subtractions</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You've got two numbers. As long as they are both larger than zero, they go through the same operation: subtract the lesser number from the larger one. If they equal substract one number from the another. For example, one operation transforms pair (4,17) to pair (4,13), it transforms (5,5) to (0,5).</p><p>You've got some number of pairs (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>). How many operations will be performed for each of them?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains the number of pairs <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 1000</span>). Then follow <span class=\"tex-span\"><i>n</i></span> lines, each line contains a pair of positive integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print the sought number of operations for each pair on a single line.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>4 17<br/>7 987654321<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br/>141093479<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"49102cebb3f63841110a2d8122e86789\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"42731265c054187dd4e7b46fc43a140f7ab5a865\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form 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class=\"header\"><div class=\"title\">A. Subtractions</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You've got two numbers. As long as they are both larger than zero, they go through the same operation: subtract the lesser number from the larger one. If they equal substract one number from the another. For example, one operation transforms pair (4,17) to pair (4,13), it transforms (5,5) to (0,5).</p><p>You've got some number of pairs (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>). How many operations will be performed for each of them?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains the number of pairs <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 1000</span>). Then follow <span class=\"tex-span\"><i>n</i></span> lines, each line contains a pair of positive integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print the sought number of operations for each pair on a single line.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />4 17<br />7 987654321<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br />141093479<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () 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etc\"]"},"short_tags":{"kind":"string","value":"[\"math\", \"number theory\", \"*900\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":1349,"cells":{"problem_id":{"kind":"string","value":"267B"},"contest":{"kind":"string","value":"267"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Dominoes"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Dominoes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You have a set of dominoes. Each domino is a rectangular tile with a line dividing its face into two square ends. Can you put all dominoes in a line one by one from left to right so that any two dominoes touched with the sides that had the same number of points? You can rotate the dominoes, changing the left and the right side (domino \"1-4\" turns into \"4-1\").</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). Next <span class=\"tex-span\"><i>n</i></span> lines contains the dominoes. Each of these lines contains two numbers — the number of points (spots) on the left and the right half, correspondingly. The numbers of points (spots) are non-negative integers from 0 to 6.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print \"<span class=\"tex-font-style-tt\">No solution</span>\", if it is impossible to arrange the dominoes in the required manner. If the solution exists, then describe any way to arrange the dominoes. You put the dominoes from left to right. In each of <span class=\"tex-span\"><i>n</i></span> lines print the index of the domino to put in the corresponding position and then, after a space, character \"<span class=\"tex-font-style-tt\">+</span>\" (if you don't need to turn the domino) or \"<span class=\"tex-font-style-tt\">–</span>\" (if you need to turn it).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>1 2<br/>2 4<br/>2 4<br/>6 4<br/>2 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2 -<br/>1 -<br/>5 -<br/>3 +<br/>4 -<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"7fa1df4442031582e99e853d747e2f42\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"42731265c054187dd4e7b46fc43a140f7ab5a865\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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(!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_199bdd9166fb985f1442bc443493a20d421db7d4\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Dominoes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You have a set of dominoes. Each domino is a rectangular tile with a line dividing its face into two square ends. Can you put all dominoes in a line one by one from left to right so that any two dominoes touched with the sides that had the same number of points? You can rotate the dominoes, changing the left and the right side (domino "1-4" turns into "4-1").</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 100</span>). Next <span class=\"tex-span\"><i>n</i></span> lines contains the dominoes. Each of these lines contains two numbers — the number of points (spots) on the left and the right half, correspondingly. The numbers of points (spots) are non-negative integers from 0 to 6.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print "<span class=\"tex-font-style-tt\">No solution</span>", if it is impossible to arrange the dominoes in the required manner. If the solution exists, then describe any way to arrange the dominoes. You put the dominoes from left to right. In each of <span class=\"tex-span\"><i>n</i></span> lines print the index of the domino to put in the corresponding position and then, after a space, character "<span class=\"tex-font-style-tt\">+</span>" (if you don't need to turn the domino) or "<span class=\"tex-font-style-tt\">–</span>" (if you need to turn it).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />1 2<br />2 4<br />2 4<br />6 4<br />2 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2 -<br />1 -<br />5 -<br />3 +<br />4 -<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = 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\"*2000\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":1350,"cells":{"problem_id":{"kind":"string","value":"267C"},"contest":{"kind":"string","value":"267"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Berland Traffic"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Berland Traffic</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Berland traffic is very different from traffic in other countries. The capital of Berland consists of <span class=\"tex-span\"><i>n</i></span> junctions and <span class=\"tex-span\"><i>m</i></span> roads. Each road connects a pair of junctions. There can be multiple roads between a pair of junctions. For each road we know its capacity: value <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> is the maximum number of cars that can drive along a road in any direction per a unit of time. For each road, the cars can drive along it in one of two direction. That it, the cars can't simultaneously move in both directions. A road's traffic is the number of cars that goes along it per a unit of time. For road (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) this value is negative, if the traffic moves from <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. A road's traffic can be a non-integer number.</p><p>The capital has two special junctions — the entrance to the city (junction 1) and the exit from the city (junction <span class=\"tex-span\"><i>n</i></span>). For all other junctions it is true that the traffic is not lost there. That is, for all junctions except for 1 and <span class=\"tex-span\"><i>n</i></span> the incoming traffic sum equals the outgoing traffic sum.</p><p>Traffic has an unusual peculiarity in the capital of Berland — for any pair of junctions (<span class=\"tex-span\"><i>x</i>, <i>y</i></span>) the sum of traffics along any path from <span class=\"tex-span\"><i>x</i></span> to <span class=\"tex-span\"><i>y</i></span> doesn't change depending on the choice of the path. Such sum includes traffic along all roads on the path (possible with the \"minus\" sign, if the traffic along the road is directed against the direction of the road on the path from <span class=\"tex-span\"><i>x</i></span> to <span class=\"tex-span\"><i>y</i></span>).</p><p>Your task is to find the largest traffic that can pass trough the city per one unit of time as well as the corresponding traffic for each road. </p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a positive integer <span class=\"tex-span\"><i>n</i></span> — the number of junctions (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>). The second line contains integer <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>m</i> ≤ 5000</span>) — the number of roads. Next <span class=\"tex-span\"><i>m</i></span> lines contain the roads' descriptions. Each road contains a group of three numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>, where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> are the numbers of junctions, connected by the given road, and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>; <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>; <span class=\"tex-span\">0 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10000</span>) is the largest permissible traffic along this road.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line print the required largest traffic across the city. Then print <span class=\"tex-span\"><i>m</i></span> lines, on each line print the speed, at which the traffic moves along the corresponding road. If the direction doesn't match the order of the junctions, given in the input, then print the traffic with the minus sign. Print the numbers with accuracy of at least five digits after the decimal point.</p><p>If there are many optimal solutions, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>3<br/>1 2 2<br/>1 2 4<br/>2 1 1000<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6.00000<br/>2.00000<br/>2.00000<br/>-2.00000<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7<br/>11<br/>1 2 7<br/>1 2 7<br/>1 3 7<br/>1 4 7<br/>2 3 7<br/>2 5 7<br/>3 6 7<br/>4 7 7<br/>5 4 7<br/>5 6 7<br/>6 7 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>13.00000<br/>2.00000<br/>2.00000<br/>3.00000<br/>6.00000<br/>1.00000<br/>3.00000<br/>4.00000<br/>7.00000<br/>1.00000<br/>2.00000<br/>6.00000<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"bf4eb9eeabe1faf6b6a81cba027c6149\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"42731265c054187dd4e7b46fc43a140f7ab5a865\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"header\"><div class=\"title\">C. Berland Traffic</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Berland traffic is very different from traffic in other countries. The capital of Berland consists of <span class=\"tex-span\"><i>n</i></span> junctions and <span class=\"tex-span\"><i>m</i></span> roads. Each road connects a pair of junctions. There can be multiple roads between a pair of junctions. For each road we know its capacity: value <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> is the maximum number of cars that can drive along a road in any direction per a unit of time. For each road, the cars can drive along it in one of two direction. That it, the cars can't simultaneously move in both directions. A road's traffic is the number of cars that goes along it per a unit of time. For road (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) this value is negative, if the traffic moves from <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. A road's traffic can be a non-integer number.</p><p>The capital has two special junctions — the entrance to the city (junction 1) and the exit from the city (junction <span class=\"tex-span\"><i>n</i></span>). For all other junctions it is true that the traffic is not lost there. That is, for all junctions except for 1 and <span class=\"tex-span\"><i>n</i></span> the incoming traffic sum equals the outgoing traffic sum.</p><p>Traffic has an unusual peculiarity in the capital of Berland — for any pair of junctions (<span class=\"tex-span\"><i>x</i>, <i>y</i></span>) the sum of traffics along any path from <span class=\"tex-span\"><i>x</i></span> to <span class=\"tex-span\"><i>y</i></span> doesn't change depending on the choice of the path. Such sum includes traffic along all roads on the path (possible with the "minus" sign, if the traffic along the road is directed against the direction of the road on the path from <span class=\"tex-span\"><i>x</i></span> to <span class=\"tex-span\"><i>y</i></span>).</p><p>Your task is to find the largest traffic that can pass trough the city per one unit of time as well as the corresponding traffic for each road. </p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a positive integer <span class=\"tex-span\"><i>n</i></span> — the number of junctions (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 100</span>). The second line contains integer <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>m</i> ≤ 5000</span>) — the number of roads. Next <span class=\"tex-span\"><i>m</i></span> lines contain the roads' descriptions. Each road contains a group of three numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>, where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> are the numbers of junctions, connected by the given road, and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>; <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>; <span class=\"tex-span\">0 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10000</span>) is the largest permissible traffic along this road.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line print the required largest traffic across the city. Then print <span class=\"tex-span\"><i>m</i></span> lines, on each line print the speed, at which the traffic moves along the corresponding road. If the direction doesn't match the order of the junctions, given in the input, then print the traffic with the minus sign. Print the numbers with accuracy of at least five digits after the decimal point.</p><p>If there are many optimal solutions, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />3<br />1 2 2<br />1 2 4<br />2 1 1000<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6.00000<br />2.00000<br />2.00000<br />-2.00000<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7<br />11<br />1 2 7<br />1 2 7<br />1 3 7<br />1 4 7<br />2 3 7<br />2 5 7<br />3 6 7<br />4 7 7<br />5 4 7<br />5 6 7<br />6 7 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>13.00000<br />2.00000<br />2.00000<br />3.00000<br />6.00000<br />1.00000<br />3.00000<br />4.00000<br />7.00000<br />1.00000<br />2.00000<br />6.00000<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () 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equations\"]"},"short_tags":{"kind":"string","value":"[\"math\", \"matrices\", \"*2700\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":1351,"cells":{"problem_id":{"kind":"string","value":"268A"},"contest":{"kind":"string","value":"268"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Games"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Games</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao works on a sports TV. He's spent much time watching the football games of some country. After a while he began to notice different patterns. For example, each team has two sets of uniforms: home uniform and guest uniform. When a team plays a game at home, the players put on the home uniform. When a team plays as a guest on somebody else's stadium, the players put on the guest uniform. The only exception to that rule is: when the home uniform color of the host team matches the guests' uniform, the host team puts on its guest uniform as well. For each team the color of the home and guest uniform is different.</p><p>There are <span class=\"tex-span\"><i>n</i></span> teams taking part in the national championship. The championship consists of <span class=\"tex-span\"><i>n</i>·(<i>n</i> - 1)</span> games: each team invites each other team to its stadium. At this point Manao wondered: how many times during the championship is a host team going to put on the guest uniform? Note that the order of the games does not affect this number.</p><p>You know the colors of the home and guest uniform for each team. For simplicity, the colors are numbered by integers in such a way that no two distinct colors have the same number. Help Manao find the answer to his question.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 30</span>). Each of the following <span class=\"tex-span\"><i>n</i></span> lines contains a pair of distinct space-separated integers <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub>, <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the colors of the <span class=\"tex-span\"><i>i</i></span>-th team's home and guest uniforms, respectively.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the number of games where the host team is going to play in the guest uniform.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>1 2<br/>2 4<br/>3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>100 42<br/>42 100<br/>5 42<br/>100 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 2<br/>1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case the championship consists of 6 games. The only game with the event in question is the game between teams 2 and 1 on the stadium of team 2.</p><p>In the second test sample the host team will have to wear guest uniform in the games between teams: 1 and 2, 2 and 1, 2 and 3, 3 and 4, 4 and 2 (the host team is written first).</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"247b009c715429d2e9d6e48926d95dbd\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"359b3372391873c3216cf1429c01c9767283fe58\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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href=\"/blog/entry/6537\" title=\"Codeforces Round #164 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1455:1456\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"http://www.codeforces.com/blog/entry/6545?locale=en\" title=\"Codeforces Round #164 (Div. 2) — Problems Analysis\" target=\"_blank\">Tutorial #1 <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1471\" resourceName=\"Codeforces Round #164 (Div. 2) — Problems Analysis\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"http://www.codeforces.com/blog/entry/6545?locale=ru\" title=\"Codeforces Round #164 (Div. 2) — Разбор задач\" target=\"_blank\">Tutorial #2 <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1469\" resourceName=\"Codeforces Round #164 (Div. 2) — Разбор задач\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/268\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/268/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/268/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/268/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/268/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/268/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/268/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/268/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n 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result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_880c35b17914f3f16cd6f4f97cd9d7b7e437f64a\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Games</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao works on a sports TV. He's spent much time watching the football games of some country. After a while he began to notice different patterns. For example, each team has two sets of uniforms: home uniform and guest uniform. When a team plays a game at home, the players put on the home uniform. When a team plays as a guest on somebody else's stadium, the players put on the guest uniform. The only exception to that rule is: when the home uniform color of the host team matches the guests' uniform, the host team puts on its guest uniform as well. For each team the color of the home and guest uniform is different.</p><p>There are <span class=\"tex-span\"><i>n</i></span> teams taking part in the national championship. The championship consists of <span class=\"tex-span\"><i>n</i>·(<i>n</i> - 1)</span> games: each team invites each other team to its stadium. At this point Manao wondered: how many times during the championship is a host team going to put on the guest uniform? Note that the order of the games does not affect this number.</p><p>You know the colors of the home and guest uniform for each team. For simplicity, the colors are numbered by integers in such a way that no two distinct colors have the same number. Help Manao find the answer to his question.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 30</span>). Each of the following <span class=\"tex-span\"><i>n</i></span> lines contains a pair of distinct space-separated integers <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub>, <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the colors of the <span class=\"tex-span\"><i>i</i></span>-th team's home and guest uniforms, respectively.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the number of games where the host team is going to play in the guest uniform.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />1 2<br />2 4<br />3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />100 42<br />42 100<br />5 42<br />100 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 2<br />1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case the championship consists of 6 games. The only game with the event in question is the game between teams 2 and 1 on the stadium of team 2.</p><p>In the second test sample the host team will have to wear guest uniform in the games between teams: 1 and 2, 2 and 1, 2 and 3, 3 and 4, 4 and 2 (the host team is written first).</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n 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1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\r\n</html>\r\n"}}},{"rowIdx":1352,"cells":{"problem_id":{"kind":"string","value":"268B"},"contest":{"kind":"string","value":"268"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Buttons"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Buttons</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao is trying to open a rather challenging lock. The lock has <span class=\"tex-span\"><i>n</i></span> buttons on it and to open it, you should press the buttons in a certain order to open the lock. When you push some button, it either stays pressed into the lock (that means that you've guessed correctly and pushed the button that goes next in the sequence), or all pressed buttons return to the initial position. When all buttons are pressed into the lock at once, the lock opens.</p><p>Consider an example with three buttons. Let's say that the opening sequence is: {2, 3, 1}. If you first press buttons 1 or 3, the buttons unpress immediately. If you first press button 2, it stays pressed. If you press 1 after 2, all buttons unpress. If you press 3 after 2, buttons 3 and 2 stay pressed. As soon as you've got two pressed buttons, you only need to press button 1 to open the lock.</p><p>Manao doesn't know the opening sequence. But he is really smart and he is going to act in the optimal way. Calculate the number of times he's got to push a button in order to open the lock in the worst-case scenario.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>A single line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 2000</span>) — the number of buttons the lock has.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the number of times Manao has to push a button in the worst-case scenario.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test sample. Manao can fail his first push and push the wrong button. In this case he will already be able to guess the right one with his second push. And his third push will push the second right button. 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class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1471\" resourceName=\"Codeforces Round #164 (Div. 2) — Problems Analysis\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"http://www.codeforces.com/blog/entry/6545?locale=ru\" title=\"Codeforces Round #164 (Div. 2) — Разбор задач\" target=\"_blank\">Tutorial #2 <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1469\" resourceName=\"Codeforces Round #164 (Div. 2) — Разбор задач\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: 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false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_98ba85dde758a0945c24cd3eaba6fcb1e74759f9\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Buttons</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao is trying to open a rather challenging lock. The lock has <span class=\"tex-span\"><i>n</i></span> buttons on it and to open it, you should press the buttons in a certain order to open the lock. When you push some button, it either stays pressed into the lock (that means that you've guessed correctly and pushed the button that goes next in the sequence), or all pressed buttons return to the initial position. When all buttons are pressed into the lock at once, the lock opens.</p><p>Consider an example with three buttons. Let's say that the opening sequence is: {2, 3, 1}. If you first press buttons 1 or 3, the buttons unpress immediately. If you first press button 2, it stays pressed. If you press 1 after 2, all buttons unpress. If you press 3 after 2, buttons 3 and 2 stay pressed. As soon as you've got two pressed buttons, you only need to press button 1 to open the lock.</p><p>Manao doesn't know the opening sequence. But he is really smart and he is going to act in the optimal way. Calculate the number of times he's got to push a button in order to open the lock in the worst-case scenario.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>A single line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 2000</span>) — the number of buttons the lock has.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the number of times Manao has to push a button in the worst-case scenario.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test sample. Manao can fail his first push and push the wrong button. In this case he will already be able to guess the right one with his second push. And his third push will push the second right button. 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'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\r\n</html>\r\n"}}},{"rowIdx":1353,"cells":{"problem_id":{"kind":"string","value":"268C"},"contest":{"kind":"string","value":"268"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Beautiful Sets of Points"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Beautiful Sets of Points</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao has invented a new mathematical term — a beautiful set of points. He calls a set of points on a plane <span class=\"tex-font-style-it\">beautiful</span> if it meets the following conditions:</p><ol> <li> The coordinates of each point in the set are integers. </li><li> For any two points from the set, the distance between them is a non-integer. </li></ol><p>Consider all points <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> which satisfy the inequations: <span class=\"tex-span\">0 ≤ <i>x</i> ≤ <i>n</i></span>; <span class=\"tex-span\">0 ≤ <i>y</i> ≤ <i>m</i></span>; <span class=\"tex-span\"><i>x</i> + <i>y</i> > 0</span>. Choose their subset of maximum size such that it is also a beautiful set of points.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 100</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line print a single integer — the size <span class=\"tex-span\"><i>k</i></span> of the found beautiful set. In each of the next <span class=\"tex-span\"><i>k</i></span> lines print a pair of space-separated integers — the <span class=\"tex-span\"><i>x</i></span>- and <span class=\"tex-span\"><i>y</i></span>- coordinates, respectively, of a point from the set.</p><p>If there are several optimal solutions, you may print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>0 1<br/>1 2<br/>2 0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/>0 3<br/>2 1<br/>3 0<br/>4 2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. The distance between points (0, 1) and (1, 2) equals <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bfe16f27ebc966df6f10ba356a1547b6e7242dd7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>, between (0, 1) and (2, 0) — <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/23d63d8a57cddda72562a512c05111054cd85870.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>, between (1, 2) and (2, 0) — <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/23d63d8a57cddda72562a512c05111054cd85870.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. Thus, these points form a beautiful set. You cannot form a beautiful set with more than three points out of the given points. Note that this is not the only solution.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"96d2f42c2d67a3d639fb85cf6e902ff8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"359b3372391873c3216cf1429c01c9767283fe58\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_f45d3451a2e6f0cefeac6876d8f7dfa10c6419f9\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Beautiful Sets of Points</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao has invented a new mathematical term — a beautiful set of points. He calls a set of points on a plane <span class=\"tex-font-style-it\">beautiful</span> if it meets the following conditions:</p><ol> <li> The coordinates of each point in the set are integers. </li><li> For any two points from the set, the distance between them is a non-integer. </li></ol><p>Consider all points <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> which satisfy the inequations: <span class=\"tex-span\">0 ≤ <i>x</i> ≤ <i>n</i></span>; <span class=\"tex-span\">0 ≤ <i>y</i> ≤ <i>m</i></span>; <span class=\"tex-span\"><i>x</i> + <i>y</i> > 0</span>. Choose their subset of maximum size such that it is also a beautiful set of points.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 100</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line print a single integer — the size <span class=\"tex-span\"><i>k</i></span> of the found beautiful set. In each of the next <span class=\"tex-span\"><i>k</i></span> lines print a pair of space-separated integers — the <span class=\"tex-span\"><i>x</i></span>- and <span class=\"tex-span\"><i>y</i></span>- coordinates, respectively, of a point from the set.</p><p>If there are several optimal solutions, you may print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />0 1<br />1 2<br />2 0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br />0 3<br />2 1<br />3 0<br />4 2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first sample. The distance between points (0, 1) and (1, 2) equals <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bfe16f27ebc966df6f10ba356a1547b6e7242dd7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, between (0, 1) and (2, 0) — <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/23d63d8a57cddda72562a512c05111054cd85870.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, between (1, 2) and (2, 0) — <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/23d63d8a57cddda72562a512c05111054cd85870.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Thus, these points form a beautiful set. You cannot form a beautiful set with more than three points out of the given points. Note that this is not the only solution.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n Codeforces.facebox(\".diff-popup\", 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Wall Bars"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Wall Bars</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>4 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao is working for a construction company. Recently, an order came to build wall bars in a children's park. Manao was commissioned to develop a plan of construction, which will enable the company to save the most money.</p><p>After reviewing the formal specifications for the wall bars, Manao discovered a number of controversial requirements and decided to treat them to the company's advantage. His resulting design can be described as follows:</p><ul> <li> Let's introduce some unit of length. The construction center is a pole of height <span class=\"tex-span\"><i>n</i></span>. </li><li> At heights <span class=\"tex-span\">1, 2, ..., <i>n</i></span> exactly one horizontal bar sticks out from the pole. Each bar sticks in one of four pre-fixed directions. </li><li> A child can move from one bar to another if the distance between them does not exceed <span class=\"tex-span\"><i>h</i></span> and they stick in the same direction. If a child is on the ground, he can climb onto any of the bars at height between <span class=\"tex-span\">1</span> and <span class=\"tex-span\"><i>h</i></span>. In Manao's construction a child should be able to reach at least one of the bars at heights <span class=\"tex-span\"><i>n</i> - <i>h</i> + 1, <i>n</i> - <i>h</i> + 2, ..., <i>n</i></span> if he begins at the ground. </li></ul><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/7b58834967c8abc6aaae3956d9cf357cb377a422.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> <span class=\"tex-font-size-script\">The figure to the left shows what a common set of wall bars looks like. The figure to the right shows Manao's construction</span> </center><p>Manao is wondering how many distinct construction designs that satisfy his requirements exist. As this number can be rather large, print the remainder after dividing it by <span class=\"tex-span\">1000000009 (10<sup class=\"upper-index\">9</sup> + 9)</span>. Two designs are considered distinct if there is such height <span class=\"tex-span\"><i>i</i></span>, that the bars on the height <span class=\"tex-span\"><i>i</i></span> in these designs don't stick out in the same direction.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>A single line contains two space-separated integers, <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>h</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 1000</span>, <span class=\"tex-span\">1 ≤ <i>h</i> ≤ <i>min</i>(<i>n</i>, 30)</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the remainder after dividing the number of designs by <span class=\"tex-span\">1000000009 (10<sup class=\"upper-index\">9</sup> + 9)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>148<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>256<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>376<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider several designs for <span class=\"tex-span\"><i>h</i> = 2</span>. A design with the first bar sticked out in direction <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\">1</sub></span>, the second — in direction <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\">2</sub></span> and so on (<span class=\"tex-span\">1 ≤ <i>d</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 4</span>) is denoted as string <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\">1</sub></span><span class=\"tex-span\"><i>d</i><sub class=\"lower-index\">2</sub></span><span class=\"tex-span\">...</span><span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>n</i></sub></span>.</p><p>Design \"1231\" (the first three bars are sticked out in different directions, the last one — in the same as first). A child can reach neither the bar at height 3 nor the bar at height 4.</p><p>Design \"414141\". A child can reach the bar at height 5. To do this, he should first climb at the first bar, then at the third and then at the fifth one. He can also reach bar at height 6 by the route second <span class=\"tex-span\"> → </span> fourth <span class=\"tex-span\"> → </span> sixth bars.</p><p>Design \"123333\". The child can't reach the upper two bars.</p><p>Design \"323323\". The bar at height 6 can be reached by the following route: first <span class=\"tex-span\"> → </span> third <span class=\"tex-span\"> → </span> fourth <span class=\"tex-span\"> → </span> sixth bars.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"49dbbebce8c35c9868d8cc3c06465349\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"359b3372391873c3216cf1429c01c9767283fe58\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_0b30b997ce1d23b7d5a3a61586a27a8116895ab2\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Wall Bars</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>4 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao is working for a construction company. Recently, an order came to build wall bars in a children's park. Manao was commissioned to develop a plan of construction, which will enable the company to save the most money.</p><p>After reviewing the formal specifications for the wall bars, Manao discovered a number of controversial requirements and decided to treat them to the company's advantage. His resulting design can be described as follows:</p><ul> <li> Let's introduce some unit of length. The construction center is a pole of height <span class=\"tex-span\"><i>n</i></span>. </li><li> At heights <span class=\"tex-span\">1, 2, ..., <i>n</i></span> exactly one horizontal bar sticks out from the pole. Each bar sticks in one of four pre-fixed directions. </li><li> A child can move from one bar to another if the distance between them does not exceed <span class=\"tex-span\"><i>h</i></span> and they stick in the same direction. If a child is on the ground, he can climb onto any of the bars at height between <span class=\"tex-span\">1</span> and <span class=\"tex-span\"><i>h</i></span>. In Manao's construction a child should be able to reach at least one of the bars at heights <span class=\"tex-span\"><i>n</i> - <i>h</i> + 1, <i>n</i> - <i>h</i> + 2, ..., <i>n</i></span> if he begins at the ground. </li></ul><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/7b58834967c8abc6aaae3956d9cf357cb377a422.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> <span class=\"tex-font-size-script\">The figure to the left shows what a common set of wall bars looks like. The figure to the right shows Manao's construction</span> </center><p>Manao is wondering how many distinct construction designs that satisfy his requirements exist. As this number can be rather large, print the remainder after dividing it by <span class=\"tex-span\">1000000009 (10<sup class=\"upper-index\">9</sup> + 9)</span>. Two designs are considered distinct if there is such height <span class=\"tex-span\"><i>i</i></span>, that the bars on the height <span class=\"tex-span\"><i>i</i></span> in these designs don't stick out in the same direction.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>A single line contains two space-separated integers, <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>h</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 1000</span>, <span class=\"tex-span\">1 ≤ <i>h</i> ≤ <i>min</i>(<i>n</i>, 30)</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the remainder after dividing the number of designs by <span class=\"tex-span\">1000000009 (10<sup class=\"upper-index\">9</sup> + 9)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>148<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>256<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>376<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider several designs for <span class=\"tex-span\"><i>h</i> = 2</span>. A design with the first bar sticked out in direction <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\">1</sub></span>, the second — in direction <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\">2</sub></span> and so on (<span class=\"tex-span\">1 ≤ <i>d</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 4</span>) is denoted as string <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\">1</sub></span><span class=\"tex-span\"><i>d</i><sub class=\"lower-index\">2</sub></span><span class=\"tex-span\">...</span><span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>n</i></sub></span>.</p><p>Design "1231" (the first three bars are sticked out in different directions, the last one — in the same as first). A child can reach neither the bar at height 3 nor the bar at height 4.</p><p>Design "414141". A child can reach the bar at height 5. To do this, he should first climb at the first bar, then at the third and then at the fifth one. He can also reach bar at height 6 by the route second <span class=\"tex-span\"> → </span> fourth <span class=\"tex-span\"> → </span> sixth bars.</p><p>Design "123333". The child can't reach the upper two bars.</p><p>Design "323323". The bar at height 6 can be reached by the following route: first <span class=\"tex-span\"> → </span> third <span class=\"tex-span\"> → </span> fourth <span class=\"tex-span\"> → </span> sixth bars.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: 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</script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'8122b03f5cea16b7',t:'MTY5NjY0NTQ3My40MTMwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) 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'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || _0xh.contentWindow.document;if (_0xi) {var _0xj = _0xi.createElement('script');_0xj.innerHTML = js;_0xi.getElementsByTagName('head')[0].appendChild(_0xj);}}if (document.readyState !== 'loading') {handler();} else if (window.addEventListener) {document.addEventListener('DOMContentLoaded', handler);} else {var prev = document.onreadystatechange || function () {};document.onreadystatechange = function (e) {prev(e);if (document.readyState !== 'loading') {document.onreadystatechange = prev;handler();}};}})();</script></body>\r\n</html>\r\n"}}},{"rowIdx":1355,"cells":{"problem_id":{"kind":"string","value":"268E"},"contest":{"kind":"string","value":"268"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Playlist"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Playlist</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao's friends often send him new songs. He never listens to them right away. Instead, he compiles them into a playlist. When he feels that his mind is open to new music, he opens the playlist and starts to listen to the songs.</p><p>Of course, there are some songs that Manao doesn't particuarly enjoy. To get more pleasure from the received songs, he invented the following procedure of listening to the playlist:</p><ul> <li> If after listening to some song Manao realizes that he liked it, then he remembers it and starts to listen to the next unlistened song. </li><li> If after listening to some song Manao realizes that he did not like it, he listens to all the songs he liked up to this point and then begins to listen to the next unlistened song. </li></ul><p>For example, if Manao has four songs in the playlist, A, B, C, D (in the corresponding order) and he is going to like songs A and C in the end, then the order of listening is the following:</p><ol> <li> Manao listens to A, he likes it, he remembers it. </li><li> Manao listens to B, he does not like it, so he listens to A, again. </li><li> Manao listens to C, he likes the song and he remembers it, too. </li><li> Manao listens to D, but does not enjoy it and re-listens to songs A and C. </li></ol><p>That is, in the end Manao listens to song A three times, to song C twice and songs B and D once. Note that if Manao once liked a song, he will never dislike it on a subsequent listening.</p><p>Manao has received <span class=\"tex-span\"><i>n</i></span> songs: the <span class=\"tex-span\"><i>i</i></span>-th of them is <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> seconds long and Manao may like it with a probability of <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> percents. The songs could get on Manao's playlist in any order, so Manao wants to know the maximum expected value of the number of seconds after which the listening process will be over, for all possible permutations of the songs in the playlist.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 50000</span>). The <span class=\"tex-span\"><i>i</i></span>-th of the following <span class=\"tex-span\"><i>n</i></span> lines contains two integers, separated by a single space — <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">15 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000</span>, <span class=\"tex-span\">0 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the length of the <span class=\"tex-span\"><i>i</i></span>-th song in seconds and the probability that Manao will like the song, in percents.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print a single real number — the maximum expected listening time over all permutations of songs. The answer will be considered valid if the absolute or relative error does not exceed <span class=\"tex-span\">10<sup class=\"upper-index\"> - 9</sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>150 20<br/>150 50<br/>100 50<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>537.500000000<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>300 0<br/>300 50<br/>240 50<br/>360 80<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2121.000000000<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test case. If Manao listens to the songs in the order in which they were originally compiled, the mathematical expectation will be equal to 467.5 seconds. The maximum expected value is obtained by putting the first song at the end of the playlist.</p><p>Consider the second test case. The song which is 360 seconds long should be listened to first. The song 300 seconds long which Manao will dislike for sure should be put in the end.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"26acfc4fad200f39edb9757fca2c1299\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"359b3372391873c3216cf1429c01c9767283fe58\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"delete-resource-link\" resourceIds=\"1469\" resourceName=\"Codeforces Round #164 (Div. 2) — Разбор задач\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/268\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/268/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/268/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/268/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/268/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/268/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/268/standings\">Standings</a></li>\r\n <li><a\r\n 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problemindex=\"E\" data-uuid=\"ps_860aff7572ce6501e7caaa341456c710b5ea7d64\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Playlist</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Manao's friends often send him new songs. He never listens to them right away. Instead, he compiles them into a playlist. When he feels that his mind is open to new music, he opens the playlist and starts to listen to the songs.</p><p>Of course, there are some songs that Manao doesn't particuarly enjoy. To get more pleasure from the received songs, he invented the following procedure of listening to the playlist:</p><ul> <li> If after listening to some song Manao realizes that he liked it, then he remembers it and starts to listen to the next unlistened song. </li><li> If after listening to some song Manao realizes that he did not like it, he listens to all the songs he liked up to this point and then begins to listen to the next unlistened song. </li></ul><p>For example, if Manao has four songs in the playlist, A, B, C, D (in the corresponding order) and he is going to like songs A and C in the end, then the order of listening is the following:</p><ol> <li> Manao listens to A, he likes it, he remembers it. </li><li> Manao listens to B, he does not like it, so he listens to A, again. </li><li> Manao listens to C, he likes the song and he remembers it, too. </li><li> Manao listens to D, but does not enjoy it and re-listens to songs A and C. </li></ol><p>That is, in the end Manao listens to song A three times, to song C twice and songs B and D once. Note that if Manao once liked a song, he will never dislike it on a subsequent listening.</p><p>Manao has received <span class=\"tex-span\"><i>n</i></span> songs: the <span class=\"tex-span\"><i>i</i></span>-th of them is <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> seconds long and Manao may like it with a probability of <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> percents. The songs could get on Manao's playlist in any order, so Manao wants to know the maximum expected value of the number of seconds after which the listening process will be over, for all possible permutations of the songs in the playlist.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a single integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 50000</span>). The <span class=\"tex-span\"><i>i</i></span>-th of the following <span class=\"tex-span\"><i>n</i></span> lines contains two integers, separated by a single space — <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">15 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 1000</span>, <span class=\"tex-span\">0 ≤ <i>p</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 100</span>) — the length of the <span class=\"tex-span\"><i>i</i></span>-th song in seconds and the probability that Manao will like the song, in percents.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print a single real number — the maximum expected listening time over all permutations of songs. The answer will be considered valid if the absolute or relative error does not exceed <span class=\"tex-span\">10<sup class=\"upper-index\"> - 9</sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />150 20<br />150 50<br />100 50<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>537.500000000<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />300 0<br />300 50<br />240 50<br />360 80<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2121.000000000<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Consider the first test case. If Manao listens to the songs in the order in which they were originally compiled, the mathematical expectation will be equal to 467.5 seconds. The maximum expected value is obtained by putting the first song at the end of the playlist.</p><p>Consider the second test case. The song which is 360 seconds long should be listened to first. 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prev;handler();}};}})();</script></body>\r\n</html>\r\n"}}},{"rowIdx":1356,"cells":{"problem_id":{"kind":"string","value":"269A"},"contest":{"kind":"string","value":"269"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Magical Boxes"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Magical Boxes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is a well-known illusionist. One of his trademark tricks involves a set of magical boxes. The essence of the trick is in packing the boxes inside other boxes.</p><p>From the top view each magical box looks like a square with side length equal to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span> (<span class=\"tex-span\"><i>k</i></span> is an integer, <span class=\"tex-span\"><i>k</i> ≥ 0</span>) units. A magical box <span class=\"tex-span\"><i>v</i></span> can be put inside a magical box <span class=\"tex-span\"><i>u</i></span>, if side length of <span class=\"tex-span\"><i>v</i></span> is strictly less than the side length of <span class=\"tex-span\"><i>u</i></span>. In particular, Emuskald can put 4 boxes of side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> - 1</sup></span> into one box of side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, or as in the following figure:</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/3c55f85e515e2d768da08019ae7e04acc3a04023.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Emuskald is about to go on tour performing around the world, and needs to pack his magical boxes for the trip. He has decided that the best way to pack them would be inside another magical box, but magical boxes are quite expensive to make. Help him find the smallest magical box that can fit all his boxes.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>), the number of different sizes of boxes Emuskald has. Each of following <span class=\"tex-span\"><i>n</i></span> lines contains two integers <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>k</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), which means that Emuskald has <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is guaranteed that all of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer <span class=\"tex-span\"><i>p</i></span>, such that the smallest magical box that can contain all of Emuskald’s boxes has side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>0 3<br/>1 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>0 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 10<br/>2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p><span class=\"tex-font-style-bf\">Picture explanation</span>. If we have 3 boxes with side length 2 and 5 boxes with side length 1, then we can put all these boxes inside a box with side length 4, for example, as shown in the picture.</p><p>In the second test case, we can put all four small boxes into a box with side length 2.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"63ff2332aeb12d7a6625ea13882389ce\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"cb5828a1f1c0dbfcac6d1115c9645e4e5e0f06ec\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Magical Boxes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is a well-known illusionist. One of his trademark tricks involves a set of magical boxes. The essence of the trick is in packing the boxes inside other boxes.</p><p>From the top view each magical box looks like a square with side length equal to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span> (<span class=\"tex-span\"><i>k</i></span> is an integer, <span class=\"tex-span\"><i>k</i> ≥ 0</span>) units. A magical box <span class=\"tex-span\"><i>v</i></span> can be put inside a magical box <span class=\"tex-span\"><i>u</i></span>, if side length of <span class=\"tex-span\"><i>v</i></span> is strictly less than the side length of <span class=\"tex-span\"><i>u</i></span>. In particular, Emuskald can put 4 boxes of side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> - 1</sup></span> into one box of side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, or as in the following figure:</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/3c55f85e515e2d768da08019ae7e04acc3a04023.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Emuskald is about to go on tour performing around the world, and needs to pack his magical boxes for the trip. He has decided that the best way to pack them would be inside another magical box, but magical boxes are quite expensive to make. Help him find the smallest magical box that can fit all his boxes.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>), the number of different sizes of boxes Emuskald has. Each of following <span class=\"tex-span\"><i>n</i></span> lines contains two integers <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>k</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), which means that Emuskald has <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is guaranteed that all of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer <span class=\"tex-span\"><i>p</i></span>, such that the smallest magical box that can contain all of Emuskald’s boxes has side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />0 3<br />1 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />0 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 10<br />2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p><span class=\"tex-font-style-bf\">Picture explanation</span>. If we have 3 boxes with side length 2 and 5 boxes with side length 1, then we can put all these boxes inside a box with side length 4, for example, as shown in the picture.</p><p>In the second test case, we can put all four small boxes into a box with side length 2.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:40</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final 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style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6645\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6596\"> <p>Codeforces Round #165 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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Greenhouse Effect"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Greenhouse Effect</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is an avid horticulturist and owns the world's longest greenhouse — it is effectively infinite in length.</p><p>Over the years Emuskald has cultivated <span class=\"tex-span\"><i>n</i></span> plants in his greenhouse, of <span class=\"tex-span\"><i>m</i></span> different plant species numbered from 1 to <span class=\"tex-span\"><i>m</i></span>. His greenhouse is very narrow and can be viewed as an infinite line, with each plant occupying a single point on that line.</p><p>Emuskald has discovered that each species thrives at a different temperature, so he wants to arrange <span class=\"tex-span\"><i>m</i> - 1</span> borders that would divide the greenhouse into <span class=\"tex-span\"><i>m</i></span> sections numbered from 1 to <span class=\"tex-span\"><i>m</i></span> from left to right with each section housing a single species. He is free to place the borders, but in the end all of the <span class=\"tex-span\"><i>i</i></span>-th species plants must reside in <span class=\"tex-span\"><i>i</i></span>-th section from the left.</p><p>Of course, it is not always possible to place the borders in such way, so Emuskald needs to replant some of his plants. He can remove each plant from its position and place it anywhere in the greenhouse (at <span class=\"tex-font-style-bf\">any</span> real coordinate) with no plant already in it. Since replanting is a lot of stress for the plants, help Emuskald find the minimum number of plants he has to replant to be able to place the borders.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 5000</span>, <span class=\"tex-span\"><i>n</i> ≥ <i>m</i></span>), the number of plants and the number of different species. Each of the following <span class=\"tex-span\"><i>n</i></span> lines contain two space-separated numbers: one integer number <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>s</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>m</i></span>), and one real number <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), the species and position of the <span class=\"tex-span\"><i>i</i></span>-th plant. Each <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> will contain no more than 6 digits after the decimal point.</p><p>It is guaranteed that all <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> are different; there is at least one plant of each species; the plants are given in order \"from left to the right\", that is in the ascending order of their <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub> < <i>x</i><sub class=\"lower-index\"><i>i</i> + 1</sub>, 1 ≤ <i>i</i> < <i>n</i>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the minimum number of plants to be replanted.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br/>2 1<br/>1 2.0<br/>1 3.100<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 5.0<br/>2 5.5<br/>3 6.0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 3<br/>1 14.284235<br/>2 17.921382<br/>1 20.328172<br/>3 20.842331<br/>1 25.790145<br/>1 27.204125<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, Emuskald can replant the first plant to the right of the last plant, so the answer is 1.</p><p>In the second test case, the species are already in the correct order, so no replanting is needed.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"10852b084b42b78f6523fb84b98a77c9\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"cb5828a1f1c0dbfcac6d1115c9645e4e5e0f06ec\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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href=\"/blog/entry/6576\" title=\"Codeforces Round #165\" target=\"_blank\">Codeforces Round #165</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1476:1480\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6596\" title=\"Разбор Codeforces Round #165\" target=\"_blank\">Tutorial #1 <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1481\" resourceName=\"Разбор Codeforces Round #165\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: 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result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_fe167f104b98a338c6f8b03ae768fef99a0272f3\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Greenhouse Effect</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is an avid horticulturist and owns the world's longest greenhouse — it is effectively infinite in length.</p><p>Over the years Emuskald has cultivated <span class=\"tex-span\"><i>n</i></span> plants in his greenhouse, of <span class=\"tex-span\"><i>m</i></span> different plant species numbered from 1 to <span class=\"tex-span\"><i>m</i></span>. His greenhouse is very narrow and can be viewed as an infinite line, with each plant occupying a single point on that line.</p><p>Emuskald has discovered that each species thrives at a different temperature, so he wants to arrange <span class=\"tex-span\"><i>m</i> - 1</span> borders that would divide the greenhouse into <span class=\"tex-span\"><i>m</i></span> sections numbered from 1 to <span class=\"tex-span\"><i>m</i></span> from left to right with each section housing a single species. He is free to place the borders, but in the end all of the <span class=\"tex-span\"><i>i</i></span>-th species plants must reside in <span class=\"tex-span\"><i>i</i></span>-th section from the left.</p><p>Of course, it is not always possible to place the borders in such way, so Emuskald needs to replant some of his plants. He can remove each plant from its position and place it anywhere in the greenhouse (at <span class=\"tex-font-style-bf\">any</span> real coordinate) with no plant already in it. Since replanting is a lot of stress for the plants, help Emuskald find the minimum number of plants he has to replant to be able to place the borders.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 5000</span>, <span class=\"tex-span\"><i>n</i> ≥ <i>m</i></span>), the number of plants and the number of different species. Each of the following <span class=\"tex-span\"><i>n</i></span> lines contain two space-separated numbers: one integer number <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>s</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>m</i></span>), and one real number <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), the species and position of the <span class=\"tex-span\"><i>i</i></span>-th plant. Each <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> will contain no more than 6 digits after the decimal point.</p><p>It is guaranteed that all <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> are different; there is at least one plant of each species; the plants are given in order "from left to the right", that is in the ascending order of their <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub> < <i>x</i><sub class=\"lower-index\"><i>i</i> + 1</sub>, 1 ≤ <i>i</i> < <i>n</i>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the minimum number of plants to be replanted.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br />2 1<br />1 2.0<br />1 3.100<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 5.0<br />2 5.5<br />3 6.0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 3<br />1 14.284235<br />2 17.921382<br />1 20.328172<br />3 20.842331<br />1 25.790145<br />1 27.204125<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, Emuskald can replant the first plant to the right of the last plant, so the answer is 1.</p><p>In the second test case, the species are already in the correct order, so no replanting is needed.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" 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href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6645\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6596\"> <p>Codeforces Round #165 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1358,"cells":{"problem_id":{"kind":"string","value":"269C"},"contest":{"kind":"string","value":"269"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Flawed Flow"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Flawed Flow</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald considers himself a master of flow algorithms. Now he has completed his most ingenious program yet — it calculates the maximum flow in an undirected graph. The graph consists of <span class=\"tex-span\"><i>n</i></span> vertices and <span class=\"tex-span\"><i>m</i></span> edges. Vertices are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>. Vertices <span class=\"tex-span\">1</span> and <span class=\"tex-span\"><i>n</i></span> being the source and the sink respectively.</p><p>However, his max-flow algorithm seems to have a little flaw — it only finds the flow volume for each edge, but not its direction. Help him find for each edge the direction of the flow through this edges. Note, that the resulting flow should be correct maximum flow.</p><p>More formally. You are given an undirected graph. For each it's undirected edge (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) you are given the flow volume <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>. You should direct all edges in such way that the following conditions hold:</p><ol> <li> for each vertex <span class=\"tex-span\"><i>v</i></span> <span class=\"tex-span\">(1 < <i>v</i> < <i>n</i>)</span>, sum of <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> of incoming edges is equal to the sum of <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> of outcoming edges; </li><li> vertex with number <span class=\"tex-span\">1</span> has no incoming edges; </li><li> the obtained directed graph <span class=\"tex-font-style-bf\">does not have cycles</span>. </li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 2·10<sup class=\"upper-index\">5</sup></span>, <span class=\"tex-span\"><i>n</i> - 1 ≤ <i>m</i> ≤ 2·10<sup class=\"upper-index\">5</sup></span>), the number of vertices and edges in the graph. The following <span class=\"tex-span\"><i>m</i></span> lines contain three space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">4</sup></span>), which means that there is an undirected edge from <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> with flow volume <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>It is guaranteed that there are no two edges connecting the same vertices; the given graph is connected; a solution always exists.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>m</i></span> lines, each containing one integer <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span>, which should be 0 if the direction of the <span class=\"tex-span\"><i>i</i></span>-th edge is <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> → <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (the flow goes from vertex <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to vertex <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) and should be 1 otherwise. The edges are numbered from 1 to <span class=\"tex-span\"><i>m</i></span> in the order they are given in the input.</p><p>If there are several solutions you can print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>3 2 10<br/>1 2 10<br/>3 1 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>0<br/>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br/>1 2 10<br/>1 3 10<br/>2 3 5<br/>4 2 15<br/>3 4 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/>0<br/>1<br/>1<br/>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, 10 flow units pass through path <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/609340f155794c4e9eebcd9cdfa23c73cf982f28.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>, and 5 flow units pass directly from source to sink: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/04481aced8a9d501ae5d785ab654c542ff5497a1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"deb9cc0bd1d33687602002c0a67667aa\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"cb5828a1f1c0dbfcac6d1115c9645e4e5e0f06ec\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6596\" title=\"Разбор Codeforces Round #165\" target=\"_blank\">Tutorial #1 <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1481\" resourceName=\"Разбор Codeforces Round #165\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/6596\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: 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result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_cb9d7d6e73ae120721a51ca909bda258981b3777\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Flawed Flow</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald considers himself a master of flow algorithms. Now he has completed his most ingenious program yet — it calculates the maximum flow in an undirected graph. The graph consists of <span class=\"tex-span\"><i>n</i></span> vertices and <span class=\"tex-span\"><i>m</i></span> edges. Vertices are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>. Vertices <span class=\"tex-span\">1</span> and <span class=\"tex-span\"><i>n</i></span> being the source and the sink respectively.</p><p>However, his max-flow algorithm seems to have a little flaw — it only finds the flow volume for each edge, but not its direction. Help him find for each edge the direction of the flow through this edges. Note, that the resulting flow should be correct maximum flow.</p><p>More formally. You are given an undirected graph. For each it's undirected edge (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) you are given the flow volume <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>. You should direct all edges in such way that the following conditions hold:</p><ol> <li> for each vertex <span class=\"tex-span\"><i>v</i></span> <span class=\"tex-span\">(1 < <i>v</i> < <i>n</i>)</span>, sum of <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> of incoming edges is equal to the sum of <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> of outcoming edges; </li><li> vertex with number <span class=\"tex-span\">1</span> has no incoming edges; </li><li> the obtained directed graph <span class=\"tex-font-style-bf\">does not have cycles</span>. </li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 2·10<sup class=\"upper-index\">5</sup></span>, <span class=\"tex-span\"><i>n</i> - 1 ≤ <i>m</i> ≤ 2·10<sup class=\"upper-index\">5</sup></span>), the number of vertices and edges in the graph. The following <span class=\"tex-span\"><i>m</i></span> lines contain three space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">4</sup></span>), which means that there is an undirected edge from <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> with flow volume <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>It is guaranteed that there are no two edges connecting the same vertices; the given graph is connected; a solution always exists.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>m</i></span> lines, each containing one integer <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span>, which should be 0 if the direction of the <span class=\"tex-span\"><i>i</i></span>-th edge is <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> → <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (the flow goes from vertex <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to vertex <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) and should be 1 otherwise. The edges are numbered from 1 to <span class=\"tex-span\"><i>m</i></span> in the order they are given in the input.</p><p>If there are several solutions you can print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />3 2 10<br />1 2 10<br />3 1 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />0<br />1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br />1 2 10<br />1 3 10<br />2 3 5<br />4 2 15<br />3 4 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br />0<br />1<br />1<br />0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, 10 flow units pass through path <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/609340f155794c4e9eebcd9cdfa23c73cf982f28.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, and 5 flow units pass directly from source to sink: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/04481aced8a9d501ae5d785ab654c542ff5497a1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1359,"cells":{"problem_id":{"kind":"string","value":"269D"},"contest":{"kind":"string","value":"269"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Maximum Waterfall"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Maximum Waterfall</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald was hired to design an artificial waterfall according to the latest trends in landscape architecture. A modern artificial waterfall consists of multiple horizontal panels affixed to a wide flat wall. The water flows down the top of the wall from panel to panel until it reaches the bottom of the wall.</p><p>The wall has height <span class=\"tex-span\"><i>t</i></span> and has <span class=\"tex-span\"><i>n</i></span> panels on the wall. Each panel is a horizontal segment at height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> which begins at <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and ends at <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>. The <span class=\"tex-span\"><i>i</i></span>-th panel connects the points <span class=\"tex-span\">(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>h</i><sub class=\"lower-index\"><i>i</i></sub>)</span> and <span class=\"tex-span\">(<i>r</i><sub class=\"lower-index\"><i>i</i></sub>, <i>h</i><sub class=\"lower-index\"><i>i</i></sub>)</span> of the plane. The top of the wall can be considered a panel connecting the points <span class=\"tex-span\">( - 10<sup class=\"upper-index\">9</sup>, <i>t</i>)</span> and <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup>, <i>t</i>)</span>. Similarly, the bottom of the wall can be considered a panel connecting the points <span class=\"tex-span\">( - 10<sup class=\"upper-index\">9</sup>, 0)</span> and <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup>, 0)</span>. No two panels share a common point.</p><p>Emuskald knows that for the waterfall to be aesthetically pleasing, it can flow from panel <span class=\"tex-span\"><i>i</i></span> to panel <span class=\"tex-span\"><i>j</i></span> (<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c59da485d3a4e463f0157335ace916b7c377dcd8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>) only if the following conditions hold: </p><ol> <li> <span class=\"tex-span\"><i>max</i>(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>l</i><sub class=\"lower-index\"><i>j</i></sub>) < <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>j</i></sub>)</span> (horizontal projections of the panels overlap); </li><li> <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>j</i></sub> < <i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> (panel <span class=\"tex-span\"><i>j</i></span> is below panel <span class=\"tex-span\"><i>i</i></span>); </li><li> there is no such panel <span class=\"tex-span\"><i>k</i></span> <span class=\"tex-span\">(<i>h</i><sub class=\"lower-index\"><i>j</i></sub> < <i>h</i><sub class=\"lower-index\"><i>k</i></sub> < <i>h</i><sub class=\"lower-index\"><i>i</i></sub>)</span> that the first two conditions hold for the pairs <span class=\"tex-span\">(<i>i</i>, <i>k</i>)</span> and <span class=\"tex-span\">(<i>k</i>, <i>j</i>)</span>. </li></ol><p>Then the <span class=\"tex-font-style-bf\">flow</span> for <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c59da485d3a4e463f0157335ace916b7c377dcd8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> is equal to <span class=\"tex-span\"><i>min</i>(<i>r</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>j</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>l</i><sub class=\"lower-index\"><i>j</i></sub>)</span>, the length of their horizontal projection overlap.</p><p>Emuskald has decided that in his waterfall the water will flow in a single path from top to bottom. If water flows to a panel (except the bottom of the wall), the water will fall further to <span class=\"tex-font-style-bf\">exactly one</span> lower panel. The total amount of water flow in the waterfall is then defined as the minimum horizontal projection overlap between two consecutive panels in the path of the waterfall. Formally: </p><ol> <li> the waterfall consists of a single path of panels <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/19e243d0761d715c71c322f6d06337878267eae8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>; </li><li> the flow of the waterfall is the minimum flow in the path <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/19e243d0761d715c71c322f6d06337878267eae8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. </li></ol><p> To make a truly great waterfall Emuskald must maximize this water flow, but there are too many panels and he is having a hard time planning his creation. Below is an example of a waterfall Emuskald wants:</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/4da5829cfd11950499f15e49228952c7f8b0ce83.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Help Emuskald maintain his reputation and find the value of the maximum possible water flow.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>, <span class=\"tex-span\">2 ≤ <i>t</i> ≤ 10<sup class=\"upper-index\">9</sup></span>), the number of the panels excluding the top and the bottom panels, and the height of the wall. Each of the <span class=\"tex-span\"><i>n</i></span> following lines contain three space-separated integers <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 < <i>h</i><sub class=\"lower-index\"><i>i</i></sub> < <i>t</i></span>, <span class=\"tex-span\"> - 10<sup class=\"upper-index\">9</sup> ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> < <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), the height, left and right ends of the <span class=\"tex-span\"><i>i</i></span>-th panel segment.</p><p>It is guaranteed that no two segments share a common point.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the maximum possible amount of water flow in the desired waterfall.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 6<br/>4 1 6<br/>3 2 7<br/>5 9 11<br/>3 10 15<br/>1 13 16<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 5<br/>4 2 8<br/>3 1 2<br/>2 2 3<br/>2 6 12<br/>1 0 7<br/>1 8 11<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first test case corresponds to the picture.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"9174c929ba01891b17873d3080bcca72\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"cb5828a1f1c0dbfcac6d1115c9645e4e5e0f06ec\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n 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value='9174c929ba01891b17873d3080bcca72'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2580\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6576\" title=\"Codeforces Round #165\" target=\"_blank\">Codeforces Round #165</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1476:1480\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6596\" title=\"Разбор Codeforces Round #165\" target=\"_blank\">Tutorial #1 <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1481\" resourceName=\"Разбор Codeforces Round #165\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/6596\" title=\"Tutorial\" target=\"_blank\">Tutorial <span 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href=\"/contest/269/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/269/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const 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class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_0822e9dfe06645d0d98af7255ee04f7830b6ca69\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Maximum Waterfall</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald was hired to design an artificial waterfall according to the latest trends in landscape architecture. A modern artificial waterfall consists of multiple horizontal panels affixed to a wide flat wall. The water flows down the top of the wall from panel to panel until it reaches the bottom of the wall.</p><p>The wall has height <span class=\"tex-span\"><i>t</i></span> and has <span class=\"tex-span\"><i>n</i></span> panels on the wall. Each panel is a horizontal segment at height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> which begins at <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and ends at <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span>. The <span class=\"tex-span\"><i>i</i></span>-th panel connects the points <span class=\"tex-span\">(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>h</i><sub class=\"lower-index\"><i>i</i></sub>)</span> and <span class=\"tex-span\">(<i>r</i><sub class=\"lower-index\"><i>i</i></sub>, <i>h</i><sub class=\"lower-index\"><i>i</i></sub>)</span> of the plane. The top of the wall can be considered a panel connecting the points <span class=\"tex-span\">( - 10<sup class=\"upper-index\">9</sup>, <i>t</i>)</span> and <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup>, <i>t</i>)</span>. Similarly, the bottom of the wall can be considered a panel connecting the points <span class=\"tex-span\">( - 10<sup class=\"upper-index\">9</sup>, 0)</span> and <span class=\"tex-span\">(10<sup class=\"upper-index\">9</sup>, 0)</span>. No two panels share a common point.</p><p>Emuskald knows that for the waterfall to be aesthetically pleasing, it can flow from panel <span class=\"tex-span\"><i>i</i></span> to panel <span class=\"tex-span\"><i>j</i></span> (<img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c59da485d3a4e463f0157335ace916b7c377dcd8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />) only if the following conditions hold: </p><ol> <li> <span class=\"tex-span\"><i>max</i>(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>l</i><sub class=\"lower-index\"><i>j</i></sub>) < <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>j</i></sub>)</span> (horizontal projections of the panels overlap); </li><li> <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>j</i></sub> < <i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> (panel <span class=\"tex-span\"><i>j</i></span> is below panel <span class=\"tex-span\"><i>i</i></span>); </li><li> there is no such panel <span class=\"tex-span\"><i>k</i></span> <span class=\"tex-span\">(<i>h</i><sub class=\"lower-index\"><i>j</i></sub> < <i>h</i><sub class=\"lower-index\"><i>k</i></sub> < <i>h</i><sub class=\"lower-index\"><i>i</i></sub>)</span> that the first two conditions hold for the pairs <span class=\"tex-span\">(<i>i</i>, <i>k</i>)</span> and <span class=\"tex-span\">(<i>k</i>, <i>j</i>)</span>. </li></ol><p>Then the <span class=\"tex-font-style-bf\">flow</span> for <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c59da485d3a4e463f0157335ace916b7c377dcd8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> is equal to <span class=\"tex-span\"><i>min</i>(<i>r</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>j</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>l</i><sub class=\"lower-index\"><i>j</i></sub>)</span>, the length of their horizontal projection overlap.</p><p>Emuskald has decided that in his waterfall the water will flow in a single path from top to bottom. If water flows to a panel (except the bottom of the wall), the water will fall further to <span class=\"tex-font-style-bf\">exactly one</span> lower panel. The total amount of water flow in the waterfall is then defined as the minimum horizontal projection overlap between two consecutive panels in the path of the waterfall. Formally: </p><ol> <li> the waterfall consists of a single path of panels <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/19e243d0761d715c71c322f6d06337878267eae8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />; </li><li> the flow of the waterfall is the minimum flow in the path <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/19e243d0761d715c71c322f6d06337878267eae8.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. </li></ol><p> To make a truly great waterfall Emuskald must maximize this water flow, but there are too many panels and he is having a hard time planning his creation. Below is an example of a waterfall Emuskald wants:</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/4da5829cfd11950499f15e49228952c7f8b0ce83.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Help Emuskald maintain his reputation and find the value of the maximum possible water flow.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>, <span class=\"tex-span\">2 ≤ <i>t</i> ≤ 10<sup class=\"upper-index\">9</sup></span>), the number of the panels excluding the top and the bottom panels, and the height of the wall. Each of the <span class=\"tex-span\"><i>n</i></span> following lines contain three space-separated integers <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>l</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 < <i>h</i><sub class=\"lower-index\"><i>i</i></sub> < <i>t</i></span>, <span class=\"tex-span\"> - 10<sup class=\"upper-index\">9</sup> ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> < <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), the height, left and right ends of the <span class=\"tex-span\"><i>i</i></span>-th panel segment.</p><p>It is guaranteed that no two segments share a common point.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the maximum possible amount of water flow in the desired waterfall.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 6<br />4 1 6<br />3 2 7<br />5 9 11<br />3 10 15<br />1 13 16<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 5<br />4 2 8<br />3 1 2<br />2 2 3<br />2 6 12<br />1 0 7<br />1 8 11<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first test case corresponds to the picture.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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String Theory"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. String Theory</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is an innovative musician and always tries to push the boundaries of music production. Now he has come up with an idea for a revolutionary musical instrument — a rectangular harp.</p><p>A rectangular harp is a rectangle <span class=\"tex-span\"><i>n</i> × <i>m</i></span> consisting of <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>m</i></span> columns. The rows are numbered 1 to <span class=\"tex-span\"><i>n</i></span> from top to bottom. Similarly the columns are numbered 1 to <span class=\"tex-span\"><i>m</i></span> from left to right. String pins are spaced evenly across every side, one per unit. Thus there are <span class=\"tex-span\"><i>n</i></span> pins on the left and right sides of the harp and <span class=\"tex-span\"><i>m</i></span> pins on its top and bottom. The harp has exactly <span class=\"tex-span\"><i>n</i> + <i>m</i></span> different strings, each string connecting two different pins, each on a different side of the harp.</p><p>Emuskald has ordered his apprentice to construct the first ever rectangular harp. However, he didn't mention that no two strings can cross, otherwise it would be impossible to play the harp. Two strings cross if the segments connecting their pins intersect. To fix the harp, Emuskald can perform operations of two types: </p><ol> <li> pick two different columns and swap their pins on each side of the harp, not changing the pins that connect each string; </li><li> pick two different rows and swap their pins on each side of the harp, not changing the pins that connect each string; </li></ol><p>In the following example, he can fix the harp by swapping two columns: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/d291af53b444c8e00b38a0c12f3a9ebe43ad409a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Help Emuskald complete his creation and find the permutations how the rows and columns of the harp need to be rearranged, or tell that it is impossible to do so. He can detach and reattach each string to its pins, so the physical layout of the strings doesn't matter.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers numbers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>), the height and width of the harp in units. Each of the following <span class=\"tex-span\"><i>n</i> + <i>m</i></span> lines contains 4 space-separated tokens, describing a single string: two symbols <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and two integer numbers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>i</i></sub></span>. The pair <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> describes the first pin, and the pair <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>i</i></sub></span> describes the second pin of the string;</p><p>A pair <span class=\"tex-span\"><i>s</i></span>, <span class=\"tex-span\"><i>x</i></span> describes the position of a single pin in a following way: </p><ol> <li> <span class=\"tex-span\"><i>s</i></span> is equal to one of the symbols \"<span class=\"tex-font-style-tt\">L</span>\", \"<span class=\"tex-font-style-tt\">T</span>\", \"<span class=\"tex-font-style-tt\">R</span>\" or \"<span class=\"tex-font-style-tt\">B</span>\" (without quotes), which means that the pin is positioned on the left, top, right or bottom side of the harp accordingly; </li><li> <span class=\"tex-span\"><i>x</i></span> is equal to the number of the row, if the pin is on the left or right border of the harp, and to the number of the column, if the pin is on the top or bottom border of the harp. </li></ol><p>It is guaranteed that no two different strings are connected to the same pin.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If it is possible to rearrange the rows and columns to fix the harp, on the first line output <span class=\"tex-span\"><i>n</i></span> space-separated integers — the old numbers of rows now placed from top to bottom in the fixed harp. On the second line, output <span class=\"tex-span\"><i>m</i></span> space-separated integers — the old numbers of columns now placed from left to right in the fixed harp.</p><p>If it is impossible to rearrange the rows and columns to fix the harp, output \"<span class=\"tex-font-style-tt\">No solution</span>\" (without quotes).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br/>L T 1 3<br/>L B 2 2<br/>L B 3 3<br/>T R 1 2<br/>T B 2 1<br/>T R 4 1<br/>B R 4 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 2 3 <br/>3 2 1 4 <br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>L T 1 1<br/>T R 3 1<br/>R B 3 3<br/>B L 1 3<br/>L R 2 2<br/>T B 2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No solution<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"eba49bcb19aa2bee3d769dc96d4c7d55\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"cb5828a1f1c0dbfcac6d1115c9645e4e5e0f06ec\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/269\">Codeforces Round 165 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/269/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Geometry, computational geometry\">\r\n geometry\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Prefix- and Z-functions, suffix structures, Knuth–Morris–Pratt algorithm, etc\">\r\n strings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *3100\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='eba49bcb19aa2bee3d769dc96d4c7d55'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2581\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='eba49bcb19aa2bee3d769dc96d4c7d55'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2581\"/>\r\n <input 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{\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6576\" title=\"Codeforces Round #165\" target=\"_blank\">Codeforces Round #165</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1476:1480\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6596\" title=\"Разбор Codeforces Round #165\" target=\"_blank\">Tutorial #1 <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1481\" resourceName=\"Разбор Codeforces Round #165\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/6596\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1609\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" 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alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. String Theory</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is an innovative musician and always tries to push the boundaries of music production. Now he has come up with an idea for a revolutionary musical instrument — a rectangular harp.</p><p>A rectangular harp is a rectangle <span class=\"tex-span\"><i>n</i> × <i>m</i></span> consisting of <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>m</i></span> columns. The rows are numbered 1 to <span class=\"tex-span\"><i>n</i></span> from top to bottom. Similarly the columns are numbered 1 to <span class=\"tex-span\"><i>m</i></span> from left to right. String pins are spaced evenly across every side, one per unit. Thus there are <span class=\"tex-span\"><i>n</i></span> pins on the left and right sides of the harp and <span class=\"tex-span\"><i>m</i></span> pins on its top and bottom. The harp has exactly <span class=\"tex-span\"><i>n</i> + <i>m</i></span> different strings, each string connecting two different pins, each on a different side of the harp.</p><p>Emuskald has ordered his apprentice to construct the first ever rectangular harp. However, he didn't mention that no two strings can cross, otherwise it would be impossible to play the harp. Two strings cross if the segments connecting their pins intersect. To fix the harp, Emuskald can perform operations of two types: </p><ol> <li> pick two different columns and swap their pins on each side of the harp, not changing the pins that connect each string; </li><li> pick two different rows and swap their pins on each side of the harp, not changing the pins that connect each string; </li></ol><p>In the following example, he can fix the harp by swapping two columns: </p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/d291af53b444c8e00b38a0c12f3a9ebe43ad409a.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Help Emuskald complete his creation and find the permutations how the rows and columns of the harp need to be rearranged, or tell that it is impossible to do so. He can detach and reattach each string to its pins, so the physical layout of the strings doesn't matter.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers numbers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup></span>), the height and width of the harp in units. Each of the following <span class=\"tex-span\"><i>n</i> + <i>m</i></span> lines contains 4 space-separated tokens, describing a single string: two symbols <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and two integer numbers <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>i</i></sub></span>. The pair <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> describes the first pin, and the pair <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>i</i></sub></span> describes the second pin of the string;</p><p>A pair <span class=\"tex-span\"><i>s</i></span>, <span class=\"tex-span\"><i>x</i></span> describes the position of a single pin in a following way: </p><ol> <li> <span class=\"tex-span\"><i>s</i></span> is equal to one of the symbols "<span class=\"tex-font-style-tt\">L</span>", "<span class=\"tex-font-style-tt\">T</span>", "<span class=\"tex-font-style-tt\">R</span>" or "<span class=\"tex-font-style-tt\">B</span>" (without quotes), which means that the pin is positioned on the left, top, right or bottom side of the harp accordingly; </li><li> <span class=\"tex-span\"><i>x</i></span> is equal to the number of the row, if the pin is on the left or right border of the harp, and to the number of the column, if the pin is on the top or bottom border of the harp. </li></ol><p>It is guaranteed that no two different strings are connected to the same pin.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If it is possible to rearrange the rows and columns to fix the harp, on the first line output <span class=\"tex-span\"><i>n</i></span> space-separated integers — the old numbers of rows now placed from top to bottom in the fixed harp. On the second line, output <span class=\"tex-span\"><i>m</i></span> space-separated integers — the old numbers of columns now placed from left to right in the fixed harp.</p><p>If it is impossible to rearrange the rows and columns to fix the harp, output "<span class=\"tex-font-style-tt\">No solution</span>" (without quotes).</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br />L T 1 3<br />L B 2 2<br />L B 3 3<br />T R 1 2<br />T B 2 1<br />T R 4 1<br />B R 4 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 2 3 <br />3 2 1 4 <br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />L T 1 1<br />T R 3 1<br />R B 3 3<br />B L 1 3<br />L R 2 2<br />T B 2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>No solution<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1361,"cells":{"problem_id":{"kind":"string","value":"270A"},"contest":{"kind":"string","value":"270"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Fancy Fence"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Fancy Fence</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald needs a fence around his farm, but he is too lazy to build it himself. So he purchased a fence-building robot.</p><p>He wants the fence to be a regular polygon. The robot builds the fence along a single path, but it can only make fence corners at a single angle <span class=\"tex-span\"><i>a</i></span>.</p><p>Will the robot be able to build the fence Emuskald wants? In other words, is there a regular polygon which angles are equal to <span class=\"tex-span\"><i>a</i></span>?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains an integer <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">0 < <i>t</i> < 180</span>) — the number of tests. Each of the following <span class=\"tex-span\"><i>t</i></span> lines contains a single integer <span class=\"tex-span\"><i>a</i></span> (<span class=\"tex-span\">0 < <i>a</i> < 180</span>) — the angle the robot can make corners at measured in degrees.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each test, output on a single line \"<span class=\"tex-font-style-tt\">YES</span>\" (without quotes), if the robot can build a fence Emuskald wants, and \"<span class=\"tex-font-style-tt\">NO</span>\" (without quotes), if it is impossible.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>30<br/>60<br/>90<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br/>YES<br/>YES<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, it is impossible to build the fence, since there is no regular polygon with angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/df5f4b07dd5316fde165b43657b2696e2919e791.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>.</p><p>In the second test case, the fence is a regular triangle, and in the last test case — a square.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"fe08fec83760b45b77bb9f90c998b2fa\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"dadcee7e066bd67f8cd93f2c830017c292cf171a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/270\">Codeforces Round 165 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/270/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Geometry, computational geometry\">\r\n geometry\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1100\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='fe08fec83760b45b77bb9f90c998b2fa'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2572\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='fe08fec83760b45b77bb9f90c998b2fa'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2572\"/>\r\n <input name=\"tagName\" 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0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/6576\" title=\"6576\" target=\"_blank\">Announcement #1 <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1472\" resourceName=\"6576\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6576\" title=\"Codeforces Round #165\" target=\"_blank\">Codeforces Round #165</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1478:1479\" resourceName=\"Announcement #2\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6596\" title=\"Разбор Codeforces Round #165\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1482\" resourceName=\"Разбор Codeforces Round #165\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/270\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/270/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/270/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/270/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/270/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/270/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/270/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/270/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_46db1f4a2377fd19cf7a9f454b3581931b01589f\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Fancy Fence</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald needs a fence around his farm, but he is too lazy to build it himself. So he purchased a fence-building robot.</p><p>He wants the fence to be a regular polygon. The robot builds the fence along a single path, but it can only make fence corners at a single angle <span class=\"tex-span\"><i>a</i></span>.</p><p>Will the robot be able to build the fence Emuskald wants? In other words, is there a regular polygon which angles are equal to <span class=\"tex-span\"><i>a</i></span>?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains an integer <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">0 < <i>t</i> < 180</span>) — the number of tests. Each of the following <span class=\"tex-span\"><i>t</i></span> lines contains a single integer <span class=\"tex-span\"><i>a</i></span> (<span class=\"tex-span\">0 < <i>a</i> < 180</span>) — the angle the robot can make corners at measured in degrees.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each test, output on a single line "<span class=\"tex-font-style-tt\">YES</span>" (without quotes), if the robot can build a fence Emuskald wants, and "<span class=\"tex-font-style-tt\">NO</span>" (without quotes), if it is impossible.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />30<br />60<br />90<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br />YES<br />YES<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, it is impossible to build the fence, since there is no regular polygon with angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/df5f4b07dd5316fde165b43657b2696e2919e791.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>In the second test case, the fence is a regular triangle, and in the last test case — a square.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" 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href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6645\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6596\"> <p>Codeforces Round #165 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1362,"cells":{"problem_id":{"kind":"string","value":"270B"},"contest":{"kind":"string","value":"270"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Multithreading"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Multithreading</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is addicted to Codeforces, and keeps refreshing the main page not to miss any changes in the \"recent actions\" list. He likes to read thread conversations where each thread consists of multiple messages.</p><p>Recent actions shows a list of <span class=\"tex-span\"><i>n</i></span> different threads ordered by the time of the latest message in the thread. When a new message is posted in a thread that thread jumps on the top of the list. No two messages of different threads are ever posted at the same time.</p><p>Emuskald has just finished reading all his opened threads and refreshes the main page for some more messages to feed his addiction. He notices that no new threads have appeared in the list and at the <span class=\"tex-span\"><i>i</i></span>-th place in the list there is a thread that was at the <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>-th place before the refresh. He doesn't want to waste any time reading old messages so he wants to open only threads with new messages.</p><p>Help Emuskald find out the number of threads that <span class=\"tex-font-style-bf\">surely</span> have new messages. A thread <span class=\"tex-span\"><i>x</i></span> surely has a new message if there is no such sequence of thread updates (posting messages) that both conditions hold: </p><ol> <li> thread <span class=\"tex-span\"><i>x</i></span> is not updated (it has no new messages); </li><li> the list order 1, 2, ..., <span class=\"tex-span\"><i>n</i></span> changes to <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>. </li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains an integer <span class=\"tex-span\"><i>n</i></span>, the number of threads (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>). The next line contains a list of <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>) is the old position of the <span class=\"tex-span\"><i>i</i></span>-th thread in the new list. It is guaranteed that all of the <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the number of threads that surely contain a new message.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>5 2 1 3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>1 2 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>4 3 2 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, threads 2 and 5 are placed before the thread 1, so these threads must contain new messages. Threads 1, 3 and 4 may contain no new messages, if only threads 2 and 5 have new messages.</p><p>In the second test case, there may be no new messages at all, since the thread order hasn't changed.</p><p>In the third test case, only thread 1 can contain no new messages.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"92d63082463ef4c0d187a6569b53e764\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"dadcee7e066bd67f8cd93f2c830017c292cf171a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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=== ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_c36d875b85237df6692c4fe237def5d9fcacd354\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Multithreading</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is addicted to Codeforces, and keeps refreshing the main page not to miss any changes in the "recent actions" list. He likes to read thread conversations where each thread consists of multiple messages.</p><p>Recent actions shows a list of <span class=\"tex-span\"><i>n</i></span> different threads ordered by the time of the latest message in the thread. When a new message is posted in a thread that thread jumps on the top of the list. No two messages of different threads are ever posted at the same time.</p><p>Emuskald has just finished reading all his opened threads and refreshes the main page for some more messages to feed his addiction. He notices that no new threads have appeared in the list and at the <span class=\"tex-span\"><i>i</i></span>-th place in the list there is a thread that was at the <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>-th place before the refresh. He doesn't want to waste any time reading old messages so he wants to open only threads with new messages.</p><p>Help Emuskald find out the number of threads that <span class=\"tex-font-style-bf\">surely</span> have new messages. A thread <span class=\"tex-span\"><i>x</i></span> surely has a new message if there is no such sequence of thread updates (posting messages) that both conditions hold: </p><ol> <li> thread <span class=\"tex-span\"><i>x</i></span> is not updated (it has no new messages); </li><li> the list order 1, 2, ..., <span class=\"tex-span\"><i>n</i></span> changes to <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>. </li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains an integer <span class=\"tex-span\"><i>n</i></span>, the number of threads (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>). The next line contains a list of <span class=\"tex-span\"><i>n</i></span> space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, ..., <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>) is the old position of the <span class=\"tex-span\"><i>i</i></span>-th thread in the new list. It is guaranteed that all of the <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the number of threads that surely contain a new message.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />5 2 1 3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />1 2 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />4 3 2 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, threads 2 and 5 are placed before the thread 1, so these threads must contain new messages. 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:40</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final 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style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6645\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6596\"> <p>Codeforces Round #165 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1363,"cells":{"problem_id":{"kind":"string","value":"270C"},"contest":{"kind":"string","value":"270"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Magical Boxes"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Magical Boxes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is a well-known illusionist. One of his trademark tricks involves a set of magical boxes. The essence of the trick is in packing the boxes inside other boxes.</p><p>From the top view each magical box looks like a square with side length equal to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span> (<span class=\"tex-span\"><i>k</i></span> is an integer, <span class=\"tex-span\"><i>k</i> ≥ 0</span>) units. A magical box <span class=\"tex-span\"><i>v</i></span> can be put inside a magical box <span class=\"tex-span\"><i>u</i></span>, if side length of <span class=\"tex-span\"><i>v</i></span> is strictly less than the side length of <span class=\"tex-span\"><i>u</i></span>. In particular, Emuskald can put 4 boxes of side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> - 1</sup></span> into one box of side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, or as in the following figure:</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/3c55f85e515e2d768da08019ae7e04acc3a04023.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>Emuskald is about to go on tour performing around the world, and needs to pack his magical boxes for the trip. He has decided that the best way to pack them would be inside another magical box, but magical boxes are quite expensive to make. Help him find the smallest magical box that can fit all his boxes.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>), the number of different sizes of boxes Emuskald has. Each of following <span class=\"tex-span\"><i>n</i></span> lines contains two integers <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>k</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), which means that Emuskald has <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is guaranteed that all of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer <span class=\"tex-span\"><i>p</i></span>, such that the smallest magical box that can contain all of Emuskald’s boxes has side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>0 3<br/>1 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>0 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 10<br/>2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p><span class=\"tex-font-style-bf\">Picture explanation</span>. If we have 3 boxes with side length 2 and 5 boxes with side length 1, then we can put all these boxes inside a box with side length 4, for example, as shown in the picture.</p><p>In the second test case, we can put all four small boxes into a box with side length 2.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b41a5326823727c8426331e26b4ba0ae\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"dadcee7e066bd67f8cd93f2c830017c292cf171a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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}\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_61e39a7d179a871046f82d5d66391b248a39e685\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Magical Boxes</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is a well-known illusionist. One of his trademark tricks involves a set of magical boxes. The essence of the trick is in packing the boxes inside other boxes.</p><p>From the top view each magical box looks like a square with side length equal to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span> (<span class=\"tex-span\"><i>k</i></span> is an integer, <span class=\"tex-span\"><i>k</i> ≥ 0</span>) units. A magical box <span class=\"tex-span\"><i>v</i></span> can be put inside a magical box <span class=\"tex-span\"><i>u</i></span>, if side length of <span class=\"tex-span\"><i>v</i></span> is strictly less than the side length of <span class=\"tex-span\"><i>u</i></span>. In particular, Emuskald can put 4 boxes of side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> - 1</sup></span> into one box of side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, or as in the following figure:</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/3c55f85e515e2d768da08019ae7e04acc3a04023.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>Emuskald is about to go on tour performing around the world, and needs to pack his magical boxes for the trip. He has decided that the best way to pack them would be inside another magical box, but magical boxes are quite expensive to make. Help him find the smallest magical box that can fit all his boxes.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup></span>), the number of different sizes of boxes Emuskald has. Each of following <span class=\"tex-span\"><i>n</i></span> lines contains two integers <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>k</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), which means that Emuskald has <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> boxes with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is guaranteed that all of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer <span class=\"tex-span\"><i>p</i></span>, such that the smallest magical box that can contain all of Emuskald’s boxes has side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />0 3<br />1 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />0 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 10<br />2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p><span class=\"tex-font-style-bf\">Picture explanation</span>. If we have 3 boxes with side length 2 and 5 boxes with side length 1, then we can put all these boxes inside a box with side length 4, for example, as shown in the picture.</p><p>In the second test case, we can put all four small boxes into a box with side length 2.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" 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href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6645\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6596\"> <p>Codeforces Round #165 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1364,"cells":{"problem_id":{"kind":"string","value":"270D"},"contest":{"kind":"string","value":"270"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Greenhouse Effect"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Greenhouse Effect</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is an avid horticulturist and owns the world's longest greenhouse — it is effectively infinite in length.</p><p>Over the years Emuskald has cultivated <span class=\"tex-span\"><i>n</i></span> plants in his greenhouse, of <span class=\"tex-span\"><i>m</i></span> different plant species numbered from 1 to <span class=\"tex-span\"><i>m</i></span>. His greenhouse is very narrow and can be viewed as an infinite line, with each plant occupying a single point on that line.</p><p>Emuskald has discovered that each species thrives at a different temperature, so he wants to arrange <span class=\"tex-span\"><i>m</i> - 1</span> borders that would divide the greenhouse into <span class=\"tex-span\"><i>m</i></span> sections numbered from 1 to <span class=\"tex-span\"><i>m</i></span> from left to right with each section housing a single species. He is free to place the borders, but in the end all of the <span class=\"tex-span\"><i>i</i></span>-th species plants must reside in <span class=\"tex-span\"><i>i</i></span>-th section from the left.</p><p>Of course, it is not always possible to place the borders in such way, so Emuskald needs to replant some of his plants. He can remove each plant from its position and place it anywhere in the greenhouse (at <span class=\"tex-font-style-bf\">any</span> real coordinate) with no plant already in it. Since replanting is a lot of stress for the plants, help Emuskald find the minimum number of plants he has to replant to be able to place the borders.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 5000</span>, <span class=\"tex-span\"><i>n</i> ≥ <i>m</i></span>), the number of plants and the number of different species. Each of the following <span class=\"tex-span\"><i>n</i></span> lines contain two space-separated numbers: one integer number <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>s</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>m</i></span>), and one real number <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), the species and position of the <span class=\"tex-span\"><i>i</i></span>-th plant. Each <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> will contain no more than 6 digits after the decimal point.</p><p>It is guaranteed that all <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> are different; there is at least one plant of each species; the plants are given in order \"from left to the right\", that is in the ascending order of their <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub> < <i>x</i><sub class=\"lower-index\"><i>i</i> + 1</sub>, 1 ≤ <i>i</i> < <i>n</i>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the minimum number of plants to be replanted.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br/>2 1<br/>1 2.0<br/>1 3.100<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 5.0<br/>2 5.5<br/>3 6.0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 3<br/>1 14.284235<br/>2 17.921382<br/>1 20.328172<br/>3 20.842331<br/>1 25.790145<br/>1 27.204125<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, Emuskald can replant the first plant to the right of the last plant, so the answer is 1.</p><p>In the second test case, the species are already in the correct order, so no replanting is needed.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4ccfa2d7633bde03490be955456e4681\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"dadcee7e066bd67f8cd93f2c830017c292cf171a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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href=\"https://codeforces.com/blog/entry/6576\" title=\"6576\" target=\"_blank\">Announcement #1 <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1472\" resourceName=\"6576\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6576\" title=\"Codeforces Round #165\" target=\"_blank\">Codeforces Round #165</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1478:1479\" resourceName=\"Announcement #2\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6596\" title=\"Разбор Codeforces Round #165\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(ru)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1482\" resourceName=\"Разбор Codeforces Round #165\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/270\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/270/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/270/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/270/status\">Status</a></li>\r\n 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return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_1e377a11b67502c3a3e6383797e226999fe91523\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Greenhouse Effect</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald is an avid horticulturist and owns the world's longest greenhouse — it is effectively infinite in length.</p><p>Over the years Emuskald has cultivated <span class=\"tex-span\"><i>n</i></span> plants in his greenhouse, of <span class=\"tex-span\"><i>m</i></span> different plant species numbered from 1 to <span class=\"tex-span\"><i>m</i></span>. His greenhouse is very narrow and can be viewed as an infinite line, with each plant occupying a single point on that line.</p><p>Emuskald has discovered that each species thrives at a different temperature, so he wants to arrange <span class=\"tex-span\"><i>m</i> - 1</span> borders that would divide the greenhouse into <span class=\"tex-span\"><i>m</i></span> sections numbered from 1 to <span class=\"tex-span\"><i>m</i></span> from left to right with each section housing a single species. He is free to place the borders, but in the end all of the <span class=\"tex-span\"><i>i</i></span>-th species plants must reside in <span class=\"tex-span\"><i>i</i></span>-th section from the left.</p><p>Of course, it is not always possible to place the borders in such way, so Emuskald needs to replant some of his plants. He can remove each plant from its position and place it anywhere in the greenhouse (at <span class=\"tex-font-style-bf\">any</span> real coordinate) with no plant already in it. Since replanting is a lot of stress for the plants, help Emuskald find the minimum number of plants he has to replant to be able to place the borders.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1 ≤ <i>n</i>, <i>m</i> ≤ 5000</span>, <span class=\"tex-span\"><i>n</i> ≥ <i>m</i></span>), the number of plants and the number of different species. Each of the following <span class=\"tex-span\"><i>n</i></span> lines contain two space-separated numbers: one integer number <span class=\"tex-span\"><i>s</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>s</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>m</i></span>), and one real number <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0 ≤ <i>x</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup></span>), the species and position of the <span class=\"tex-span\"><i>i</i></span>-th plant. Each <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> will contain no more than 6 digits after the decimal point.</p><p>It is guaranteed that all <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> are different; there is at least one plant of each species; the plants are given in order "from left to the right", that is in the ascending order of their <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>i</i></sub> < <i>x</i><sub class=\"lower-index\"><i>i</i> + 1</sub>, 1 ≤ <i>i</i> < <i>n</i>)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output a single integer — the minimum number of plants to be replanted.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br />2 1<br />1 2.0<br />1 3.100<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 5.0<br />2 5.5<br />3 6.0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 3<br />1 14.284235<br />2 17.921382<br />1 20.328172<br />3 20.842331<br />1 25.790145<br />1 27.204125<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, Emuskald can replant the first plant to the right of the last plant, so the answer is 1.</p><p>In the second test case, the species are already in the correct order, so no replanting is needed.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" 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href=\"/profile/gen\">gen</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/gen\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/gen\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/gen\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/gen\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/gen\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/gen\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/gen\" style=\"text-decoration:none;color:black !important;\">gen's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6645\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6596\"> <p>Codeforces Round #165 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a>,\r\n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1365,"cells":{"problem_id":{"kind":"string","value":"270E"},"contest":{"kind":"string","value":"270"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Flawed Flow"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Flawed Flow</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald considers himself a master of flow algorithms. Now he has completed his most ingenious program yet — it calculates the maximum flow in an undirected graph. The graph consists of <span class=\"tex-span\"><i>n</i></span> vertices and <span class=\"tex-span\"><i>m</i></span> edges. Vertices are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>. Vertices <span class=\"tex-span\">1</span> and <span class=\"tex-span\"><i>n</i></span> being the source and the sink respectively.</p><p>However, his max-flow algorithm seems to have a little flaw — it only finds the flow volume for each edge, but not its direction. Help him find for each edge the direction of the flow through this edges. Note, that the resulting flow should be correct maximum flow.</p><p>More formally. You are given an undirected graph. For each it's undirected edge (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) you are given the flow volume <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>. You should direct all edges in such way that the following conditions hold:</p><ol> <li> for each vertex <span class=\"tex-span\"><i>v</i></span> <span class=\"tex-span\">(1 < <i>v</i> < <i>n</i>)</span>, sum of <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> of incoming edges is equal to the sum of <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> of outcoming edges; </li><li> vertex with number <span class=\"tex-span\">1</span> has no incoming edges; </li><li> the obtained directed graph <span class=\"tex-font-style-bf\">does not have cycles</span>. </li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 2·10<sup class=\"upper-index\">5</sup></span>, <span class=\"tex-span\"><i>n</i> - 1 ≤ <i>m</i> ≤ 2·10<sup class=\"upper-index\">5</sup></span>), the number of vertices and edges in the graph. The following <span class=\"tex-span\"><i>m</i></span> lines contain three space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">4</sup></span>), which means that there is an undirected edge from <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> with flow volume <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>It is guaranteed that there are no two edges connecting the same vertices; the given graph is connected; a solution always exists.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>m</i></span> lines, each containing one integer <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span>, which should be 0 if the direction of the <span class=\"tex-span\"><i>i</i></span>-th edge is <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> → <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (the flow goes from vertex <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to vertex <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) and should be 1 otherwise. The edges are numbered from 1 to <span class=\"tex-span\"><i>m</i></span> in the order they are given in the input.</p><p>If there are several solutions you can print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>3 2 10<br/>1 2 10<br/>3 1 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>0<br/>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br/>1 2 10<br/>1 3 10<br/>2 3 5<br/>4 2 15<br/>3 4 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/>0<br/>1<br/>1<br/>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, 10 flow units pass through path <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/609340f155794c4e9eebcd9cdfa23c73cf982f28.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>, and 5 flow units pass directly from source to sink: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/04481aced8a9d501ae5d785ab654c542ff5497a1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"bf1294b6ca4c499a3ec364290abfef6f\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"dadcee7e066bd67f8cd93f2c830017c292cf171a\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"header\"><div class=\"title\">E. Flawed Flow</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Emuskald considers himself a master of flow algorithms. Now he has completed his most ingenious program yet — it calculates the maximum flow in an undirected graph. The graph consists of <span class=\"tex-span\"><i>n</i></span> vertices and <span class=\"tex-span\"><i>m</i></span> edges. Vertices are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>. Vertices <span class=\"tex-span\">1</span> and <span class=\"tex-span\"><i>n</i></span> being the source and the sink respectively.</p><p>However, his max-flow algorithm seems to have a little flaw — it only finds the flow volume for each edge, but not its direction. Help him find for each edge the direction of the flow through this edges. Note, that the resulting flow should be correct maximum flow.</p><p>More formally. You are given an undirected graph. For each it's undirected edge (<span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) you are given the flow volume <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>. You should direct all edges in such way that the following conditions hold:</p><ol> <li> for each vertex <span class=\"tex-span\"><i>v</i></span> <span class=\"tex-span\">(1 < <i>v</i> < <i>n</i>)</span>, sum of <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> of incoming edges is equal to the sum of <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> of outcoming edges; </li><li> vertex with number <span class=\"tex-span\">1</span> has no incoming edges; </li><li> the obtained directed graph <span class=\"tex-font-style-bf\">does not have cycles</span>. </li></ol></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of input contains two space-separated integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2 ≤ <i>n</i> ≤ 2·10<sup class=\"upper-index\">5</sup></span>, <span class=\"tex-span\"><i>n</i> - 1 ≤ <i>m</i> ≤ 2·10<sup class=\"upper-index\">5</sup></span>), the number of vertices and edges in the graph. The following <span class=\"tex-span\"><i>m</i></span> lines contain three space-separated integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\">1 ≤ <i>c</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">4</sup></span>), which means that there is an undirected edge from <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> with flow volume <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>It is guaranteed that there are no two edges connecting the same vertices; the given graph is connected; a solution always exists.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>m</i></span> lines, each containing one integer <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span>, which should be 0 if the direction of the <span class=\"tex-span\"><i>i</i></span>-th edge is <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub> → <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (the flow goes from vertex <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> to vertex <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>) and should be 1 otherwise. The edges are numbered from 1 to <span class=\"tex-span\"><i>m</i></span> in the order they are given in the input.</p><p>If there are several solutions you can print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />3 2 10<br />1 2 10<br />3 1 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />0<br />1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br />1 2 10<br />1 3 10<br />2 3 5<br />4 2 15<br />3 4 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br />0<br />1<br />1<br />0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first test case, 10 flow units pass through path <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/609340f155794c4e9eebcd9cdfa23c73cf982f28.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, and 5 flow units pass directly from source to sink: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/04481aced8a9d501ae5d785ab654c542ff5497a1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2b4468df01c6a46df7ea30f45aff02f3'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Feb/02/2013 20:44\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"/contest/270/problem/A\" title=\"270A - Fancy Fence\">Div II A — Fancy Fence</a></h3><h4>Problem</h4><p>The problem is to tell whether there exists a regular polygon with angle equal to <span class=\"tex-span\"><i>a</i></span>.</p><h4>Solution</h4><p>Consider all supplementary angles of the regular <span class=\"tex-span\"><i>n</i></span>-polygon with angle <span class=\"tex-span\"><i>a</i></span>, which are equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Their sum is equal to <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59ce64504a539e9d03c517dadecc05e6f00dcdac.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, because the polygon is convex. Then the following equality holds: <span class=\"tex-span\"><i>n</i>·(180 - <i>a</i>) = 360</span>, which means that there is an answer if and only if <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/b31268ac1d8f499f469cdb6ee50c1831de7ff96c.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p><img alt=\" \" src=\"/predownloaded/02/bf/02bffc0ce34dcc260dee7244bb5af6c0c29e9427.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>t</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/xnq9Iu\">C++</a>, <a href=\"http://ideone.com/D2hHEL\">Java</a></p><h4>Comments</h4><p>The problem can be also solved by rotating vector <span class=\"tex-span\">(1, 0)</span> by angle <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bc8faf5afc069d757de0afc3b4b5cb2723fc15ee.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> until it returns in this position (but at most 360 times), and checking that only one full turn has been made (implementation example: C++).</p><p>It is also a rare problem on Codeforces that contains just 1 sample test, 1 pretest and 1 full test.</p><h3><a href=\"/contest/270/problem/B\" title=\"270B - Multithreading\">Div II B — Multithreading</a></h3><h4>Problem</h4><p>In this problem we are asked to find the number of <span class=\"tex-span\"><i>n</i></span>-permutation elements that definitely have been moved after performing any sequence of move-to-front element operations. Equally, we should find the maximum possible number of elements that could have not been moved.</p><h4>Solution</h4><p>If some <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is greater than <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>, it is clear that <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> definitely contains a new message because the order of these two elements has changed. Let the last such element be <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span>. Then all of the elements <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 1</sub></span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i> + 2</sub></span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> can contain no new messages, since their order has not changed. The answer to the problem is <span class=\"tex-span\"><i>n</i> - <i>k</i></span>. If there is no such <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>k</i></sub></span> the order hasn’t changed at all and there may be no new messages.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>) / <i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/PJFbnJ\">C++</a>, <a href=\"http://ideone.com/0DR19E\">Java</a></p><h4>Comments</h4><p>The problem was born while staring at the Codeforces main page and trying to think up an easy Div II problem. =)</p><h3><a href=\"/contest/269/problem/A\" title=\"269A - Magical Boxes\">Div II C / Div I A — Magical Boxes</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. It is allowed to insert squares only inside larger ones, and no two squares should overlap. We must determine the minimum <span class=\"tex-span\"><i>p</i></span> so we can place all the given squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>.</p><h4>Solution</h4><p>Suppose we can put all the squares inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>p</i></sup></span>. Then we can insert each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> type squares independently along the grid as shown in the picture. No two squares will overlap, since <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> divides <span class=\"tex-span\">2<sup class=\"upper-index\"><i>y</i></sup></span>, if <span class=\"tex-span\"><i>x</i> < <i>y</i></span>. That means that we can find the smallest square that can hold all the given squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for each <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> separately. The answer will be the side length of the largest such square.</p><p><img alt=\" \" src=\"/predownloaded/53/5c/535cf4b4af3f1c515e8da48607760d55499e5c62.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>To be able to put <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> squares with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> inside a square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>s</i></sup></span>, the following should hold:</p> <center><span class=\"tex-span\">(2<sup class=\"upper-index\"><i>s</i></sup>)<sup class=\"upper-index\">2</sup> ≥ (2<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>)<sup class=\"upper-index\">2</sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i></sup> ≥ 4<sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>·<i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center> <center><span class=\"tex-span\">4<sup class=\"upper-index\"><i>s</i> - <i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup> ≥ <i>a</i><sub class=\"lower-index\"><i>i</i></sub></span></center><p>We can then find the minimum <span class=\"tex-span\"><i>s</i></span>:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/59f61e375813af2caf90154799cd8f3a16a83f2e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/fe368bf5e969f0339b9b5e2df4934721792e254d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>In a special case, if we obtain <span class=\"tex-span\"><i>s</i> = <i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>s</i></span> should be increased by 1.</p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/752fc15d42f06b3e7ac8f636f79bf7894ec73b23.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(1)</span>.</p><p>Implementation: <a href=\"http://ideone.com/NORd3X\">C++</a>, <a href=\"http://ideone.com/Zp7Nno\">Java</a></p><h4>Comments</h4><p>The problem can be also solved using binary search on <span class=\"tex-span\"><i>p</i></span>. However, we can see that each square with side length <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i> + 15</sup></span> holds any number of squares with side length less than <span class=\"tex-span\">2<sup class=\"upper-index\"><i>k</i></sup></span>, since <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/462a71d7eab39c443fe8ffaf5e057aa055d894b3.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So it is enough to find the first square that fits from range <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 1</sup></span> to <span class=\"tex-span\">2<sup class=\"upper-index\"><i>max</i>{<i>k</i>} + 15</sup></span>.</p><h3><a href=\"/contest/269/problem/B\" title=\"269B - Greenhouse Effect\">Div II D / Div I B — Greenhouse Effect</a></h3><h4>Problem</h4><p>There are <span class=\"tex-span\"><i>n</i></span> points on the line, each of type from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span>. We can freely divide the line into <span class=\"tex-span\"><i>m</i> - 1</span> intervals and replace some points so each point with type <span class=\"tex-span\"><i>i</i></span> is inside the <span class=\"tex-span\"><i>i</i></span>-th interval numbered <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from left to right. We must find the minimum number of points to replace.</p><h4>Solution</h4><p>First, observe that the coordinates don’t matter: only the order of the points is important. Let there be some number of points we can replace to achieve the good arrangement. Then all the other points remain in their positions, so their values must be in increasing order from left to right. Then we must find the maximum number of points that can remain in their positions, which is the longest non-decreasing subsequence of types in the input. If it is of length <span class=\"tex-span\"><i>l</i></span>, the answer is <span class=\"tex-span\"><i>n</i> - <i>l</i></span>.</p><p>In this problem it was enough to implement a quadratic solution. We count <span class=\"tex-span\"><i>dp</i>[<i>i</i>][<i>j</i>]</span> — the length of the longest non-decreasing subsequence on prefix <span class=\"tex-span\">[1;<i>i</i>]</span>, with element of type <span class=\"tex-span\"><i>j</i></span> being the last in subsequence. The transition is as follows:</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/7037e675ca92c1993453bdebc162574fe68ee567.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>For easy implementation, we can maintain only array <span class=\"tex-span\"><i>dp</i>[<i>j</i>]</span>, and skip the second case.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i><sup class=\"upper-index\">2</sup>)</span> / <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/8uzrrr\">C++</a></p><h4>Comments</h4><p>We had to solve this problem during the work on our project, the origin lies in arranging some rectangular table borders. Our original project dp implementation actually runs in <span class=\"tex-span\"><i>O</i>(<i>nm</i>)</span>.</p><h3><a href=\"/contest/269/problem/C\" title=\"269C - Flawed Flow\">Div II E / Div I C — Flawed Flow</a></h3><h4>Problem</h4><p>In this problem we are given an undirected graph and its flow, and we must reconstruct the edge directions of this flow.</p><h4>Solution</h4><p>The key element to solving the task is the following observation: if we know all the incoming edges of a vertex, all the remaining edges must be outgoing. The source has no incoming edges, so we already know that all its edges are outgoing. For all other vertices except the sink the amount of incoming and outcoming flow is the same, and is equal to half of the sum of the flow along its incident edges. The algorithm then is to repeatedly direct all the flow from the vertices for which all the incoming edges are known. This can be done with a single BFS:</p> <pre><code>for all v from 2 to n-1\n f[v] := sum(flow(v,u))/2;\nput source in queue\nwhile queue is not empty\n v := pop(queue)\n for all edges (v, u)\n if (v, u) is not directed yet\n direct v -> u\n f[u] = f[u] - flow(v,u)\n if u not sink and f[u] = 0\n push(queue, u)\n</code></pre><p>As the flow contains no cycles, we can sort the vertices topologically. Then we can be sure that, until all edge directions are known, we can put at least the first vertex with unknown edges in the queue, as all of its incoming edges will be from vertices with lower indices, but we took the first vertex with unknown edges.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/ePdlwd\">C++</a>, <a href=\"http://ideone.com/qE3vYO\">Java</a></p><h4>Comments</h4><p>The obvious "easy" solution is to run some maxflow algorithm and get the answer. However, such implementations failed on anti-maxflow pretest #6.</p><h3><a href=\"/contest/269/problem/D\" title=\"269D - Maximum Waterfall\">Div I D — Maximum Waterfall</a></h3><h4>Problem</h4><p>We are given <span class=\"tex-span\"><i>n</i></span> horizontal segments on a plane, and 2 extra topmost and bottommost segments. These two segments are the source and the sink of the flow. A flow can pass from one segment to a lower segment, if their horizontal projections overlap and there is no other segment between them so their projections overlap. The value of the flow on such segment edge is equal to the length of the horizontal projection overlap. We must find the maximum possible value of the flow along a single segment path.</p><h4>Solution</h4><p>We will use a sweepline algorithm to solve this task. This horizontal sweepline runs from bottom to top, and holds the parts of the segments that are visible from the line this sweepline is currently at. Each part also holds the reference to its original segment. The sweepline itself is implemented with a binary search tree.</p><p>The events of the sweep are the segments. When a new segment is found, we want to find all the lower segments that we can direct the flow onto from this segment. These can be only the original segments of the parts currently in the sweepline whose projections overlap with this segment. Then we iterate over all such parts <span class=\"tex-span\"><i>p</i></span> (finding the first such part is an <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9040a33098f83986b0de64475c66584fbfdf0e22.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> operation). How do we know that we can direct the flow onto <span class=\"tex-span\"><i>p</i></span>? Observe that if there is some segment that prevents this, there should be also a part <span class=\"tex-span\"><i>q</i></span> in the sweepline that also can be seen from the current segment. And since the projections of all three segments overlap, this part can only be directly to the left or to the right of <span class=\"tex-span\"><i>p</i></span> in the binary search tree. So we just check whether the original segments of the two parts next to <span class=\"tex-span\"><i>p</i></span> prevent the flow from the current segment to the original segment of <span class=\"tex-span\"><i>p</i></span>.</p><p>Afterwards, we remove all such parts from the sweepline, and insert a new part corresponding to the new segment. If the new segment only partially covered an existing part, we reinsert the remaining portion of that part. There are at most two such portions — one on each side of the segment. Thus each segment inserts at most 3 new parts and the size of the sweepline is <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span>. Each part is handled just once before removal, so the total time of such operations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</p><p>Once we know we can direct the flow through <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/a6fb1c4b6c53481175e27cd77b2c49e794ca9037.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> we can immediately update the maximum downwards flow of <span class=\"tex-span\"><i>a</i></span>:</p> <center><span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>a</i></sub> = <i>max</i>(<i>f</i><sub class=\"lower-index\"><i>a</i></sub>, <i>min</i>(<i>f</i><sub class=\"lower-index\"><i>b</i></sub>, <i>min</i>(<i>r</i><sub class=\"lower-index\"><i>a</i></sub>, <i>r</i><sub class=\"lower-index\"><i>b</i></sub>) - <i>max</i>(<i>l</i><sub class=\"lower-index\"><i>a</i></sub>, <i>l</i><sub class=\"lower-index\"><i>b</i></sub>)))</span></center><p>When we reach the top, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>top</i></sub></span> will be the answer.</p><p><img alt=\" \" src=\"/predownloaded/c2/88/c288d19923212b3628e2f66ff35a029ac03f3aae.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Time: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5e7dae7c1838af7ba7570bdf02ff61029b043be6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i>)</span></p><p>Implementation: <a href=\"http://ideone.com/bka28U\">C++</a>, <a href=\"http://ideone.com/frmAwe\">Java</a></p><h4>Comments</h4><p>Another problem from our project. You can also first build a graph from the segments using the same sweepline and then find the path with the maximum flow in that graph. In the original problem you have to find this graph and there are no top and bottom segments.</p><h3><a href=\"/contest/269/problem/E\" title=\"269E - String Theory\">Div I E — String Theory</a></h3><h4>Problem</h4><p>In this problem we have an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> rectange. Each unit midpoint is connected with a segment to some other midpoint not on the same side of the rectangle. We can change the order of the columns and rows, but the segments must remain attached to their midpoints. We should find such a rearrangement that no two segments intersect, or tell that there is no solution.</p><h4>Solution</h4><p>There are overall 6 types of segments that connect the sides:</p> <ol> <li>left-top;</li> <li>top-right;</li> <li>right-bottom;</li> <li>bottom-left;</li> <li>left-right;</li> <li>top-bottom;</li> </ol><p>If there are both left-right and top-bottom segments, there is no solution. Otherwise there remain only 5 types of segments. Without loss of generality suppose there are no left-right segments. Let’s take a closer look at what should the end picture of the rectangle be:</p><p><img alt=\" \" src=\"/predownloaded/be/b7/beb76baf14cfbcb1b4bc25d301e5989ca199b422.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>All left-top segments should be at the left top corner connecting positions (L,i) and (T,i), otherwise they surely would cross some other segment. Similarly must be positioned top-right, right-bottom, bottom-left segments. Finally, all top-bottom segments should be parallel. We also observe that the number of left-top segments must be equal to the number of right-bottom segments and the number of top-right segments should be equal to the number of bottom-right segments. Thus the important observation: the picture of the end arrangement is unique and can be determined from the input simply by counting the number of segments of each type.</p><p>Next we define a cycle to be the sequence of segments, where the second midpoint of some segment in the cycle is equal to the first midpoint in the next segment in the cycle. In the given example there are two such cycles (but the direction of each cycle actually matters):</p><p><img alt=\" \" src=\"/predownloaded/d9/a5/d9a506bacbc331c38b443ef718e94ef87b363a6c.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Then we observe that the set of the cycles does not change with any permutation by the definition of the cycle. We can make a sketch of the solution: we should find the cycle sets in the given arrangement and in the end arrangement, and compare them for equality.</p><p>At this point we actually find all the cycles in both arrangements. There are only two types of cycles:</p> <ol> <li>(left-top) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (right-bottom) <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (bottom-left);</li> <li>other cycles.</li> </ol><p>We can easily check whether the sets of first type cycles match, since the length of such cycles is 4. If they match, we rearrange the columns and rows involved to match the end arrangement.</p><p>How to compare the remaining cycles. Consider a following example:</p><p><img alt=\" \" src=\"/predownloaded/94/6e/946e914c948f9ec9e2a1511a3c1200b27b5437b7.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>Let the difference in the number of left-top and left-bottom segments be <span class=\"tex-span\"><i>i</i></span>, and this number plus the number of top-bottom segments <span class=\"tex-span\"><i>s</i></span>. If we enumerate the midpoints as in the figure, we can see that each top midpoint <span class=\"tex-span\"><i>k</i></span> is connected to the bottom midpoint <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/0dac9193462da45923bae2b6116c78d4cdd7e2f7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> (top-right segments continue as corresponding left-bottom segments). Thus we can describe it as a permutation</p> <center><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9c3f0435e143337663d84b515eeea4f1f0194615.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></center><p>Our cycles correspond to the cycles in this permutation, with top-right segment continuation to left-bottom segment corresponding to the case where permutation cycle element decreases. It is known that the number of such permutations is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/1462393223571a0965b949d22c8fceea3055d6d7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> and their length is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/e0d7fda515893df8302ac175bd85f929a7ddfc34.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. So all these cycles have the same length. Denote the remaining segment types as some letters (in picture A, B, C). Then not only the length, but the strings describing the cycles are also the same, but can be shifted cyclically (here the direction of the cycles also is important). Besides, we know this string from the correct arrangement cycle. Thus we need to compare all the remaining given arrangement cycle strings to this string, considering cyclic shifts as invariant transformations. For each string this can be done in linear time, for example, using the Knuth-Morris-Pratt algorithm. When we find a cyclical shift for each cycle, we can position its relevant columns and rows according to the end arrangement.</p><p>Time: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Memory: <span class=\"tex-span\"><i>O</i>(<i>n</i> + <i>m</i>)</span>.</p><p>Implementation: <a href=\"http://ideone.com/bm0GQP\">C++</a>, <a href=\"http://ideone.com/QYJR6c\">Java</a></p><h4>Comments</h4><p>This is a total killer task for coding. It took both of us around 5 hours to code the implementation. Congratulations again to <a class=\"rated-user user-red\" href=\"/profile/kelvin\" title=\"Grandmaster kelvin\">kelvin</a>, at the time of writing still the only one to solve the problem (and of course to anyone who will get this difficult problem accepted =) ).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/269\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 165 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-426-6645\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"426\",\n blogEntryId: \"6596\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=165\" class=\"tag notice\" style=\"text-decoration: none;\">165</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+88</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6645\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/gen\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/gen\">\n gen\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/02/2013 20:44\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6596#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6596#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6655\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120899\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingofnumbers\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingofnumbers\" title=\"Grandmaster kingofnumbers\" class=\"rated-user user-red\">kingofnumbers</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 02:40\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120899\" href=\"?#comment-120899\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120899\" class=\"CommentVoteFrame\"\r\n class=\"too-negative-comment-vote\"\r\n data-commentRating=\"-35\"\r\n data-commentUserId=\"67432\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-35</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120899\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I really wish that I didn't see problem like Div1 E , it made me sad.</p><p>I think it's harder than IOI problems.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120899 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120899 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120899\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120986\" commentParentId=\"120899\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dixtosa\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/67797/avatar/ce2bd3bf38f9c8c7.jpg'/> </a>\n <div><a href=\"/profile/Dixtosa\" title=\"Specialist Dixtosa\" class=\"rated-user user-cyan\">Dixtosa</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120986\" href=\"?#comment-120986\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120899\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120986\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"67797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120986\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How hard are problems there? IOI?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120986 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120986 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120986\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120906\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/guguli\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49085/avatar/744b10e87f6071fa.jpg'/> </a>\n <div><a href=\"/profile/guguli\" title=\"Expert guguli\" class=\"rated-user user-blue\">guguli</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 12:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120906\" href=\"?#comment-120906\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120906\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"19\"\r\n data-commentUserId=\"49085\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+19</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120906\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was a little hard to prove the needed algorithm for your problems but that was easy to code them , thanks .</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120906 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120906 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120906\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120977\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Kaga2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Kaga2\" title=\"Expert Kaga2\" class=\"rated-user user-blue\">Kaga2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:20\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120977\" href=\"?#comment-120977\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120977\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"25568\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120977\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>That is true that the anti-maxflow pretest #6 kill my Dinic implementation, however the Push-Relabel of <a class=\"rated-user user-violet\" href=\"/profile/tsfn\" title=\"Candidate Master tsfn\">tsfn</a> pass all the data sets, including the anti-maxflow pretest. <a href=\"/contest/269/submission/3053014\" title=\"Submission 3053014 by tsfn\">3053014</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120977 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120977 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120977\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120981\" commentParentId=\"120977\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1169/avatar/50ff70649f205823.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/gen\" title=\"Master gen\" class=\"rated-user user-orange\">gen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/03/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120981\" href=\"?#comment-120981\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120977\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120981\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"1169\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120981\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ahhh! This is much faster than our push-relabel implementation, but also very close to TL (1937 ms).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120981 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120981 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120981\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121462\" commentParentId=\"120981\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/abhimanyu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/abhimanyu\" title=\"Expert abhimanyu\" class=\"rated-user user-blue\">abhimanyu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121462\" href=\"?#comment-121462\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120981\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121462\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"78447\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121462\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Could we not solve the Flawed Flow problem just by finding Max flow in graph, and deciding edge direction by direction of flow(value of flow +ve or -ve) ?</p><p>Yes your solution is easy and fast. But just asking about other possibility.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121462 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121462 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121462\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120994\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 04:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120994\" href=\"?#comment-120994\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120994\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120994\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>for div1 c, is there a proof that as long as you are not finished directing the graph, there will always be a vertex v where f[v]=0?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120994 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120994 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120994\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120999\" commentParentId=\"120994\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 10:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120999\" href=\"?#comment-120999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120994\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"120999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>note that wa have an acyclic graph in problem statement </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121029\" commentParentId=\"120999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 19:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121029\" href=\"?#comment-121029\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121029\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121029\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>why does an acyclic graph guarantee that there will always be v s.t. f[v]=0? i.e. that all of v's incoming edges are known</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121029 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121029 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121029\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121055\" commentParentId=\"121029\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/MMJ\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/52190/avatar/16d565dbc8d1471.jpg'/> </a>\n <div><a href=\"/profile/MMJ\" title=\"Expert MMJ\" class=\"rated-user user-blue\">MMJ</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:34\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121055\" href=\"?#comment-121055\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121029\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121055\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121055\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"9\"\r\n data-commentUserId=\"52190\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+9</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121055\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>if there's no vertex v that f[v]=0 then we have an cycle in graph, because every vertex in graph have at least one incoming edge. (Consider longest simple path in remain graph, we know that head vertex in path has an incoming edge and the head of that edge is also in path).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121055 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121055 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121055\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121056\" commentParentId=\"121055\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lawsonh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/lawsonh\" title=\"Expert lawsonh\" class=\"rated-user user-blue\">lawsonh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 00:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121056\" href=\"?#comment-121056\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121055\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121056\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"55047\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121056\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121056 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121056 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121056\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"120995\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 06:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-120995\" href=\"?#comment-120995\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"120995\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"120995\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-120995\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/gen\" title=\"Expert gen\">gen</a> , thanks for writing a very clear editorial!</p><p>For div1 B, if we just need to divide the line into m intervals where each interval must only have one type BUT type i can be within each of the m intervals(in contrast to must be inside interval i in the original problem), then how to solve it? For this variant, sample 1 would be:</p><p>input</p><p>3 2</p><p>2 1</p><p>1 2.0</p><p>1 3.100</p><p>output</p><p>0</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-120995 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-120995 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-120995\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121054\" commentParentId=\"120995\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ikbal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/57334/avatar/956b6d718e3af4cc.jpg'/> </a>\n <div><a href=\"/profile/ikbal\" title=\"Master ikbal\" class=\"rated-user user-orange\">ikbal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/04/2013 23:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121054\" href=\"?#comment-121054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-120995\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"57334\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>"He is free to place the borders, but in the end all of the i-th species plants must reside in i-th section from the left."</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121125\" commentParentId=\"121054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/pjag\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73881/avatar/88f5f8af3cc0703c.jpg'/> </a>\n <div><a href=\"/profile/pjag\" title=\"Candidate Master pjag\" class=\"rated-user user-violet\">pjag</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 18:47\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121125\" href=\"?#comment-121125\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-121054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121125\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73881\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121125\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>He knows this. He just wonders how to solve it when we change the problem slightly.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121125 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121125 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121125\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121072\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KIDx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50913/avatar/e69bbae0098c6cae.jpg'/> </a>\n <div><a href=\"/profile/KIDx\" title=\"Expert KIDx\" class=\"rated-user user-blue\">KIDx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/05/2013 11:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121072\" href=\"?#comment-121072\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"121072\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"121072\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50913\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121072\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For Magical Boxes, I ignored that the box can't fill itself. T-T</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121072 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121072 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121072\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"121322\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hza\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50083/avatar/33c0e8a67fd20700.jpg'/> </a>\n <div><a href=\"/profile/hza\" title=\"Master hza\" class=\"rated-user user-orange\">hza</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/07/2013 14:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-121322\" href=\"?#comment-121322\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"121322\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"50083\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-121322\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I wonder the relation of E and Planar graph.Maybe we can use planar embedding of the graph to solve it.Just kidding lol!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-121322 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-121322 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-121322\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"401850\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/KtlTheBest\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/240230/avatar/d7765c3c37517896.jpg'/> </a>\n <div><a href=\"/profile/KtlTheBest\" title=\"Specialist KtlTheBest\" class=\"rated-user user-cyan\">KtlTheBest</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Dec/21/2017 06:49\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-401850\" href=\"?#comment-401850\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"401850\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"240230\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-401850\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello, guys. Can someone explain how can we solve Div1 B in O(NlogN)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-401850 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-401850 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-401850\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"405053\" commentParentId=\"401850\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/gaurav15\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/gaurav15\" title=\"Expert gaurav15\" class=\"rated-user user-blue\">gaurav15</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/02/2018 12:47\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-405053\" href=\"?#comment-405053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-401850\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"405053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"456314\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-405053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can find length of LIS in O(NlogN). <a href=\"http://lightoj.com/article_show.php?article=1000&language=english&type=pdf\">http://lightoj.com/article_show.php?article=1000&language=english&type=pdf</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-405053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-405053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-405053\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"485963\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/21/2019 07:40\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-485963\" href=\"?#comment-485963\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"485963\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-485963\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>A point to note here is that the algorithm used for Div2 E / Div1 C is not a bfs. Though it proceeds like a bfs; it does not guarantee that a vertex is put in the queue when it is first observed contrary to bfs. Also we can use any data structure (not necessarily a queue) to store the vertices for which all incoming edges are known like stack, set, priority_queue, etc.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-485963 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-485963 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-485963\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6655\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":1366,"cells":{"problem_id":{"kind":"string","value":"271A"},"contest":{"kind":"string","value":"271"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Beautiful Year"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Beautiful Year</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>It seems like the year of 2013 came only yesterday. Do you know a curious fact? The year of 2013 is the first year after the old 1987 with only distinct digits.</p><p>Now you are suggested to solve the following problem: given a year number, find the minimum year number which is strictly larger than the given one and has only distinct digits.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line contains integer <span class=\"tex-span\"><i>y</i></span> <span class=\"tex-span\">(1000 ≤ <i>y</i> ≤ 9000)</span> — the year number.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the minimum year number that is strictly larger than <span class=\"tex-span\"><i>y</i></span> and all it's digits are distinct. It is guaranteed that the answer exists.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1987<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2013<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2013<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2014<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"2abf9a78ec777fdab18f394e3fe3de6b\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"386e484be27a0ae7443e874543a82306c9570e72\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/271/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='2abf9a78ec777fdab18f394e3fe3de6b'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2617\"/>\r\n <input name=\"tagName\" type=\"hidden\" 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href=\"/blog/entry/6659\" title=\"Codeforces Round #166 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1490:1491\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6662\" title=\"6662\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1489:21793\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/271\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/271/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/271/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/271/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/271/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/271/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/271/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/271/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n 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const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_89ccb0ef0fab6712314d95cf95c4e856e1c94a23\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Beautiful Year</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>It seems like the year of 2013 came only yesterday. Do you know a curious fact? The year of 2013 is the first year after the old 1987 with only distinct digits.</p><p>Now you are suggested to solve the following problem: given a year number, find the minimum year number which is strictly larger than the given one and has only distinct digits.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The single line contains integer <span class=\"tex-span\"><i>y</i></span> <span class=\"tex-span\">(1000 ≤ <i>y</i> ≤ 9000)</span> — the year number.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the minimum year number that is strictly larger than <span class=\"tex-span\"><i>y</i></span> and all it's digits are distinct. It is guaranteed that the answer exists.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1987<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2013<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2013<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2014<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='a1d4cd739c5a24c027443e72b228f37b'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/RAD\">RAD</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/RAD\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/RAD\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/RAD\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/RAD\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/RAD\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/RAD\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/RAD\" style=\"text-decoration:none;color:black !important;\">RAD's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6711\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6662\"> <p>Codeforces Round #166 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a>,\r\n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/271/problem/A\" title=\"Codeforces Round 166 (Div. 2)\">271A - Beautiful Year</a></p><p>This is a very straight forward problem. Just add 1 to a year number while it still has equal digits.</p><p><a href=\"/contest/271/problem/B\" title=\"Codeforces Round 166 (Div. 2)\">271B - Prime Matrix</a></p><p>Precalculate the next prime for every integer from <span class=\"tex-span\">1</span> to <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>. You can do that in any way. The main thing is to test all the divisors up to square root when you are checking if a number is prime.</p><p>Now for each <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> (element of the given matrix) we can easily calculate <span class=\"tex-span\"><i>add</i><sub class=\"lower-index\"><i>ij</i></sub></span> — how many do we have to add in order to make <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> prime. After that all we need to do is to find row or column with minimal sum in this new matrix.</p><p><a href=\"/contest/271/problem/C\" title=\"Codeforces Round 166 (Div. 2)\">271C - Secret</a></p><p>If <span class=\"tex-span\">3<i>k</i> > <i>n</i></span> there is no solution (because each of the <span class=\"tex-span\"><i>k</i></span> sets must have at least 3 elements). Otherwise we can divide first <span class=\"tex-span\">3<i>k</i></span> words in the following way:</p><p><code>1 1 2 2 3 3 ... k k 1 2 3 ... k</code></p><p>For each of the <span class=\"tex-span\"><i>k</i></span> sets, the difference between the first and the second elements will be <span class=\"tex-span\">1</span>. And the difference between the second and the third elements is definitely not <span class=\"tex-span\">1</span> (more precisely, it is <span class=\"tex-span\">2<i>k</i> - <i>i</i> - 1</span> for the <span class=\"tex-span\"><i>i</i></span>-th set). So each set doesn't form an arithmetic progression for sure.</p><p>For this solution it doesn't matter how we divide the rest <span class=\"tex-span\"><i>n</i> - 3<i>k</i></span> words.</p><p><a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a></p><p>At first, build a <a href=\"https://en.wikipedia.org/wiki/Trie\">trie</a> containing all suffixes of given string (this structure is also called explicit suffix tree). Let's iterate over all substrings in order of indexes' increasing, i. e. first <span class=\"tex-span\">[1...1], </span> then <span class=\"tex-span\">[1...2], [1...3], ..., [1...<i>n</i>], [2...2], [2...3], ..., [2...<i>n</i>], ...</span> Note, that moving from a substring to the next one is just adding a single character to the end. So we can easily maintain the number of bad characters, and also the "current" node in the trie. If the number of bad characters doesn't exceed <span class=\"tex-span\"><i>k</i></span>, then the substring is good. And we need to mark the corresponding node of trie, if we never did this before. The answer will be the number of marked nodes in the trie.</p><p>There is also an easier solution, where instead of trie we use <a href=\"https://en.wikipedia.org/wiki/Rolling_hash\">Rabin-Karp rolling hash</a> to count substrings that differ by content. Just sort the hashes of all good substrings and find the number of unique hashes (equal hashes will be on adjacent positions after sort). But these hashes are unreliable in general, so it's always better to use precise algorithm.</p><p><a href=\"/contest/271/problem/E\" title=\"Codeforces Round 166 (Div. 2)\">271E - Three Horses</a></p><p>It could be proved, that a card <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> <span class=\"tex-span\">(<i>x</i> < <i>y</i>)</span> can be transformed to any card <span class=\"tex-span\">(1, 1 + <i>k</i>·<i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is the maximal odd divisor of <span class=\"tex-span\"><i>y</i> - <i>x</i></span>, and <span class=\"tex-span\"><i>k</i></span> is just any positive integer. So every <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\"><i>i</i></sub> - 1)</span> must be divisible by <span class=\"tex-span\"><i>d</i></span>, i. e. <span class=\"tex-span\"><i>d</i></span> is a divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and we can just iterate over all possible divisors. Let's take a look at all the initial cards <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, which have have <span class=\"tex-span\"><i>d</i></span> as their maximal odd divisor: these are cards with <span class=\"tex-span\"><i>y</i> - <i>x</i></span> equal to <span class=\"tex-span\"><i>d</i></span>, or <span class=\"tex-span\">2<i>d</i></span>, or <span class=\"tex-span\">4<i>d</i></span>, <span class=\"tex-span\">8<i>d</i></span>, <span class=\"tex-span\">16<i>d</i></span>, ... Don't forget that the numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> must not exceed <span class=\"tex-span\"><i>m</i></span>. It means that the total number of cards with some fixed difference <span class=\"tex-span\"><i>t</i> = <i>y</i> - <i>x</i></span> is exactly <span class=\"tex-span\"><i>m</i> - <i>t</i></span>.</p><p>The resulting solution: sum up <span class=\"tex-span\">(<i>m</i> - 2<sup class=\"upper-index\"><i>l</i></sup><i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is any odd divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and <span class=\"tex-span\"><i>l</i></span> is such, that <span class=\"tex-span\">2<sup class=\"upper-index\"><i>l</i></sup><i>d</i> ≤ <i>m</i></span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/271\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 166 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-173-6711\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"173\",\n blogEntryId: \"6662\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces+round\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=166\" class=\"tag notice\" style=\"text-decoration: none;\">166</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+39</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/RAD\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/RAD\">\n RAD\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6662#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6662#comments\">\n 46\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6721\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (27)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122173\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fura2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4118/avatar/98f7ddceb1dac755.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/fura2\" title=\"Master fura2\" class=\"rated-user user-orange\">fura2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 17:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122173\" href=\"?#comment-122173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4118\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is there any background in problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122173\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122203\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 21:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122203\" href=\"?#comment-122203\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122203\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122203\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 4rth q after so many TLE's I have drawn an inference that generally map is slower than set though both being dynamic memory allocation....</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122203 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122203 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122203\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122208\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122208\" href=\"?#comment-122208\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122208\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122208\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm quiet new in Java,I keep getting TLE and use trie data structure,any advises?(Though the same code written in C++ got AC) <a href=\"//codeforces.com/contest/271/submission/3109415\">code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122208 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122208 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122208\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122210\" commentParentId=\"122208\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122210\" href=\"?#comment-122210\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122208\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122210\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122210\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's not because you use Java, it's because you make a lot of substring() calls.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122210 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122210 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122210\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122211\" commentParentId=\"122210\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122211\" href=\"?#comment-122211\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122210\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122211\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122211\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks,so is there a faster way to remove the first character from string?Or i should use array of chars instead of strings or something like that</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122211 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122211 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122211\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122213\" commentParentId=\"122211\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122213\" href=\"?#comment-122213\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122211\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122213\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122213\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just remember where the string really begins.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122213 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122213 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122213\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122214\" commentParentId=\"122213\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122214\" href=\"?#comment-122214\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122213\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122214\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122214\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yup thanks got it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122214 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122214 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122214\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122525\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/syc0\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83057/avatar/3738e52d646e03e3.jpg'/> </a>\n <div><a href=\"/profile/syc0\" title=\"Pupil syc0\" class=\"rated-user user-green\">syc0</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 06:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122525\" href=\"?#comment-122525\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122525\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"83057\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122525\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i m not getting the problem E' editorial can any one explain ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122525 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122525 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122525\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"501419\" commentParentId=\"122525\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/23/2019 08:28\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-501419\" href=\"?#comment-501419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122525\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"501419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-501419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/6659?#comment-122056\">Here</a> is the proof for the solution given in the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-501419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-501419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-501419\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karthick\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/77362/avatar/2b6285094c5d5b71.jpg'/> </a>\n <div><a href=\"/profile/karthick\" title=\"Pupil karthick\" class=\"rated-user user-green\">karthick</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122591\" href=\"?#comment-122591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77362\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem 4, suffix array with lcp can also be used. We can first pre-compute the bad character count for all the substrings and store it in a table. Then, iterating through the suffix array and avoiding duplicate substrings using the lcp table, we can find the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122591\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122993\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122993\" href=\"?#comment-122993\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122993\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122993\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello. I am having trouble with the problem D (getting TLE). I am using the trie to solve the problem. When I build it, I already keep track of the current number of bad characters. If it is bigger than <em>k</em>, I leave the recursion. The final answer is the number of nodes of the tree.</p><p>Could anyone help me please? What am I doing wrong? <a href=\"//www.codeforces.com/contest/271/submission/3141412\">Code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122993 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122993 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122993\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122999\" commentParentId=\"122993\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/RAD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/397/avatar/8f89de4ecdba5051.jpg'/> </a>\n <div><a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122999\" href=\"?#comment-122999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122993\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why do you have these 2 nested loops in main() function? You are not really using <code>i</code> anywhere.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123013\" commentParentId=\"122999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 23:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123013\" href=\"?#comment-123013\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123013\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123013\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OMG, thanks RAD. It was something I was trying and forgot to remove.</p> <pre><code>for (int i = 0; i < n; ++i)\n{\n put(t, s + i);\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123013 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123013 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123013\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123094\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 07:39\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123094\" href=\"?#comment-123094\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123094\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123094\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C: in each set Ui, its elements ui, 1, ui, 2, ..., ui, |Ui| do not form an arithmetic progression (in particular, |Ui| ≥ 3 should hold). What's the meaning of it ? Does it means when Ui < 3 there is no necessary to hold this condition ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123094 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123094 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123094\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123097\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123097\" href=\"?#comment-123097\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123097\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123097\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you tell me what's wrong of my code ? Problem D: <a href=\"/contest/271/submission/3145554\" title=\"Submission 3145554 by water\">3145554</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123097 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123097 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123097\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123098\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:36\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123098\" href=\"?#comment-123098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Complexity</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123098\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123101\" commentParentId=\"123098\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123101\" href=\"?#comment-123101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123098\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think so, I learned from this AC submission? Why his is ok ? <a href=\"/contest/271/submission/3105181\" title=\"Submission 3105181 by a142857a\">3105181</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123102\" commentParentId=\"123101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 11:35\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123102\" href=\"?#comment-123102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try to find out what is the complexity of string comparisons</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123102\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"639472\" commentParentId=\"123102\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rudraksh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1170856/avatar/c5e36802b8507472.jpg'/> </a>\n <div><a href=\"/profile/Rudraksh\" title=\"Specialist Rudraksh\" class=\"rated-user user-cyan\">Rudraksh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2020 11:21\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-639472\" href=\"?#comment-639472\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123102\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"639472\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1170856\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-639472\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>so you're saying that insertion in set is taking time??</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-639472 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-639472 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-639472\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"661611\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/samarth9421\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/samarth9421\" title=\"Specialist samarth9421\" class=\"rated-user user-cyan\">samarth9421</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2020 20:07\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-661611\" href=\"?#comment-661611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"661611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1473183\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-661611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can implement it using sets but I think you have to iterate for len =1 to len=n and index 0 to n-len; after every len you have to clear your set to prevent it from exceeding memory limit</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-661611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-661611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-661611\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"366943\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ananth94\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/211746/avatar/72fbf14db6a1bcdc.jpg'/> </a>\n <div><a href=\"/profile/ananth94\" title=\"Specialist ananth94\" class=\"rated-user user-cyan\">ananth94</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2017 11:34\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-366943\" href=\"?#comment-366943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"366943\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"366943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"211746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-366943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D <a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a> : This is my code. I've used the concept of Rolling hash/Rabin Karp algorithm. But I guess there are some collisions happening and it's failing on test case number 8. Any help is greatly appreciated. Been trying this for a long time. </p><p>Code: <a href=\"/contest/271/submission/27820412\" title=\"Submission 27820412 by ananth94\">27820412</a></p><p>Update: Solved! I tried many different ways. Initially, I used two hash moduli instead of one, but this exceeded the Time Limit on test #8 (Which is weird!). I ended up using a really large prime (About the size of 2^50) which just passed the time limit for Testcase #8 and passed the cases as well. :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-366943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-366943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-366943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1037670\" commentParentId=\"366943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-VIBE\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2362415/avatar/7491393ac045f895.jpg'/> </a>\n <div><a href=\"/profile/-VIBE\" title=\"Expert -VIBE\" class=\"rated-user user-blue\">-VIBE</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2023 15:08\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1037670\" href=\"?#comment-1037670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-366943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1037670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2362415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1037670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya i was also getting wrong answer due to collisions so just used two different numbers 31 and 67 with modulo 1e9+7 and it got accepted </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1037670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1037670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1037670\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"466405\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingside\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingside\" title=\"Specialist kingside\" class=\"rated-user user-cyan\">kingside</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/24/2018 14:30\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-466405\" href=\"?#comment-466405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"466405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"378817\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-466405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D can be solved using 2 pointer and little bit of a lcp array.This is my solution. <a href=\"https://codeforces.com/contest/271/submission/44768791\">https://codeforces.com/contest/271/submission/44768791</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-466405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-466405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-466405\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"543325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aryan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/920094/avatar/c3ccd87908c923db.jpg'/> </a>\n <div><a href=\"/profile/aryan29\" title=\"Expert aryan29\" class=\"rated-user user-blue\">aryan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2019 23:23\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-543325\" href=\"?#comment-543325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"543325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"920094\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-543325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D is like using 2 hashes of 10^9 size-TLE Using 1hash of 10^9 size -WA and using a very big hash and multiplying recursive -TLE</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-543325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-543325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-543325\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arsalan9911\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1221235/avatar/7bd5179da6faa5e0.jpg'/> </a>\n <div><a href=\"/profile/arsalan9911\" title=\"Newbie arsalan9911\" class=\"rated-user user-gray\">arsalan9911</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 10:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552357\" href=\"?#comment-552357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"552357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1221235\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Beautiful Year</strong> <a href=\"https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year\">https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552368\" commentParentId=\"552357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 13:16\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552368\" href=\"?#comment-552368\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-552357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"552368\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"552368\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552368\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hey. Please stop spamming on every tutorial blog with your solutions of Div2 A problems. There are already many solutions available in the submissions section. You're not helping anyone at all. You're just spamming and also unnecessarily bringing old posts in the <strong>Recent Actions</strong> section.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552368 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552368 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552368\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"570233\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dsxv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/783201/avatar/b0756b3a28cbd94e.jpg'/> </a>\n <div><a href=\"/profile/Dsxv\" title=\"Expert Dsxv\" class=\"rated-user user-blue\">Dsxv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/03/2020 02:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-570233\" href=\"?#comment-570233\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"570233\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"783201\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-570233\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>271D using Z algorithm: <a href=\"https://codeforces.com/contest/271/submission/68098565\">https://codeforces.com/contest/271/submission/68098565</a></p><p>prereq: distinct substring using Z ( read it from CP algo ).</p><p>Implementation: Now I am assuming you know distinct substr using Z, then: we start counting the answer for a prefix after the zmax of that prefix. ( because we'll have distinct substring only after zmax)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-570233 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-570233 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-570233\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6721\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span 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Prime Matrix"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Prime Matrix</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You've got an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> matrix. The matrix consists of integers. In one move, you can apply a single transformation to the matrix: choose an arbitrary element of the matrix and increase it by <span class=\"tex-span\">1</span>. Each element can be increased an arbitrary number of times.</p><p>You are really curious about prime numbers. Let us remind you that a <span class=\"tex-font-style-it\">prime number</span> is a positive integer that has exactly two distinct positive integer divisors: itself and number one. For example, numbers 2, 3, 5 are prime and numbers 1, 4, 6 are not. </p><p>A matrix is <span class=\"tex-font-style-it\">prime</span> if at least one of the two following conditions fulfills:</p><ul> <li> the matrix has a row with prime numbers only; </li><li> the matrix has a column with prime numbers only; </li></ul><p>Your task is to count the minimum number of moves needed to get a prime matrix from the one you've got.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i>, <i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 500)</span> — the number of rows and columns in the matrix, correspondingly.</p><p>Each of the following <span class=\"tex-span\"><i>n</i></span> lines contains <span class=\"tex-span\"><i>m</i></span> integers — the initial matrix. All matrix elements are positive integers. All numbers in the initial matrix do not exceed <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>.</p><p>The numbers in the lines are separated by single spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the minimum number of moves needed to get a prime matrix from the one you've got. If you've got a prime matrix, print 0.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 2 3<br/>5 6 1<br/>4 4 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 3<br/>4 8 8<br/>9 2 9<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br/>1 3<br/>4 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample you need to increase number 1 in cell (1, 1). Thus, the first row will consist of prime numbers: 2, 2, 3.</p><p>In the second sample you need to increase number 8 in cell (1, 2) three times. Thus, the second column will consist of prime numbers: 11, 2.</p><p>In the third sample you don't have to do anything as the second column already consists of prime numbers: 3, 2. </p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"bccd2f3d2bef8ea99dace9c0f1a8dadc\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"386e484be27a0ae7443e874543a82306c9570e72\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"header\"><div class=\"title\">B. Prime Matrix</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You've got an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> matrix. The matrix consists of integers. In one move, you can apply a single transformation to the matrix: choose an arbitrary element of the matrix and increase it by <span class=\"tex-span\">1</span>. Each element can be increased an arbitrary number of times.</p><p>You are really curious about prime numbers. Let us remind you that a <span class=\"tex-font-style-it\">prime number</span> is a positive integer that has exactly two distinct positive integer divisors: itself and number one. For example, numbers 2, 3, 5 are prime and numbers 1, 4, 6 are not. </p><p>A matrix is <span class=\"tex-font-style-it\">prime</span> if at least one of the two following conditions fulfills:</p><ul> <li> the matrix has a row with prime numbers only; </li><li> the matrix has a column with prime numbers only; </li></ul><p>Your task is to count the minimum number of moves needed to get a prime matrix from the one you've got.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i>, <i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 500)</span> — the number of rows and columns in the matrix, correspondingly.</p><p>Each of the following <span class=\"tex-span\"><i>n</i></span> lines contains <span class=\"tex-span\"><i>m</i></span> integers — the initial matrix. All matrix elements are positive integers. All numbers in the initial matrix do not exceed <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>.</p><p>The numbers in the lines are separated by single spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the minimum number of moves needed to get a prime matrix from the one you've got. If you've got a prime matrix, print 0.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 2 3<br />5 6 1<br />4 4 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 3<br />4 8 8<br />9 2 9<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br />1 3<br />4 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample you need to increase number 1 in cell (1, 1). Thus, the first row will consist of prime numbers: 2, 2, 3.</p><p>In the second sample you need to increase number 8 in cell (1, 2) three times. 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='a1d4cd739c5a24c027443e72b228f37b'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/RAD\">RAD</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/RAD\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/RAD\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/RAD\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/RAD\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/RAD\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/RAD\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/RAD\" style=\"text-decoration:none;color:black !important;\">RAD's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6711\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6662\"> <p>Codeforces Round #166 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a>,\r\n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/271/problem/A\" title=\"Codeforces Round 166 (Div. 2)\">271A - Beautiful Year</a></p><p>This is a very straight forward problem. Just add 1 to a year number while it still has equal digits.</p><p><a href=\"/contest/271/problem/B\" title=\"Codeforces Round 166 (Div. 2)\">271B - Prime Matrix</a></p><p>Precalculate the next prime for every integer from <span class=\"tex-span\">1</span> to <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>. You can do that in any way. The main thing is to test all the divisors up to square root when you are checking if a number is prime.</p><p>Now for each <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> (element of the given matrix) we can easily calculate <span class=\"tex-span\"><i>add</i><sub class=\"lower-index\"><i>ij</i></sub></span> — how many do we have to add in order to make <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> prime. After that all we need to do is to find row or column with minimal sum in this new matrix.</p><p><a href=\"/contest/271/problem/C\" title=\"Codeforces Round 166 (Div. 2)\">271C - Secret</a></p><p>If <span class=\"tex-span\">3<i>k</i> > <i>n</i></span> there is no solution (because each of the <span class=\"tex-span\"><i>k</i></span> sets must have at least 3 elements). Otherwise we can divide first <span class=\"tex-span\">3<i>k</i></span> words in the following way:</p><p><code>1 1 2 2 3 3 ... k k 1 2 3 ... k</code></p><p>For each of the <span class=\"tex-span\"><i>k</i></span> sets, the difference between the first and the second elements will be <span class=\"tex-span\">1</span>. And the difference between the second and the third elements is definitely not <span class=\"tex-span\">1</span> (more precisely, it is <span class=\"tex-span\">2<i>k</i> - <i>i</i> - 1</span> for the <span class=\"tex-span\"><i>i</i></span>-th set). So each set doesn't form an arithmetic progression for sure.</p><p>For this solution it doesn't matter how we divide the rest <span class=\"tex-span\"><i>n</i> - 3<i>k</i></span> words.</p><p><a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a></p><p>At first, build a <a href=\"https://en.wikipedia.org/wiki/Trie\">trie</a> containing all suffixes of given string (this structure is also called explicit suffix tree). Let's iterate over all substrings in order of indexes' increasing, i. e. first <span class=\"tex-span\">[1...1], </span> then <span class=\"tex-span\">[1...2], [1...3], ..., [1...<i>n</i>], [2...2], [2...3], ..., [2...<i>n</i>], ...</span> Note, that moving from a substring to the next one is just adding a single character to the end. So we can easily maintain the number of bad characters, and also the "current" node in the trie. If the number of bad characters doesn't exceed <span class=\"tex-span\"><i>k</i></span>, then the substring is good. And we need to mark the corresponding node of trie, if we never did this before. The answer will be the number of marked nodes in the trie.</p><p>There is also an easier solution, where instead of trie we use <a href=\"https://en.wikipedia.org/wiki/Rolling_hash\">Rabin-Karp rolling hash</a> to count substrings that differ by content. Just sort the hashes of all good substrings and find the number of unique hashes (equal hashes will be on adjacent positions after sort). But these hashes are unreliable in general, so it's always better to use precise algorithm.</p><p><a href=\"/contest/271/problem/E\" title=\"Codeforces Round 166 (Div. 2)\">271E - Three Horses</a></p><p>It could be proved, that a card <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> <span class=\"tex-span\">(<i>x</i> < <i>y</i>)</span> can be transformed to any card <span class=\"tex-span\">(1, 1 + <i>k</i>·<i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is the maximal odd divisor of <span class=\"tex-span\"><i>y</i> - <i>x</i></span>, and <span class=\"tex-span\"><i>k</i></span> is just any positive integer. So every <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\"><i>i</i></sub> - 1)</span> must be divisible by <span class=\"tex-span\"><i>d</i></span>, i. e. <span class=\"tex-span\"><i>d</i></span> is a divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and we can just iterate over all possible divisors. Let's take a look at all the initial cards <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, which have have <span class=\"tex-span\"><i>d</i></span> as their maximal odd divisor: these are cards with <span class=\"tex-span\"><i>y</i> - <i>x</i></span> equal to <span class=\"tex-span\"><i>d</i></span>, or <span class=\"tex-span\">2<i>d</i></span>, or <span class=\"tex-span\">4<i>d</i></span>, <span class=\"tex-span\">8<i>d</i></span>, <span class=\"tex-span\">16<i>d</i></span>, ... Don't forget that the numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> must not exceed <span class=\"tex-span\"><i>m</i></span>. It means that the total number of cards with some fixed difference <span class=\"tex-span\"><i>t</i> = <i>y</i> - <i>x</i></span> is exactly <span class=\"tex-span\"><i>m</i> - <i>t</i></span>.</p><p>The resulting solution: sum up <span class=\"tex-span\">(<i>m</i> - 2<sup class=\"upper-index\"><i>l</i></sup><i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is any odd divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and <span class=\"tex-span\"><i>l</i></span> is such, that <span class=\"tex-span\">2<sup class=\"upper-index\"><i>l</i></sup><i>d</i> ≤ <i>m</i></span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/271\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 166 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-173-6711\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"173\",\n blogEntryId: \"6662\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces+round\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=166\" class=\"tag notice\" style=\"text-decoration: none;\">166</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+39</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/RAD\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/RAD\">\n RAD\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6662#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6662#comments\">\n 46\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6721\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (27)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122173\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fura2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4118/avatar/98f7ddceb1dac755.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/fura2\" title=\"Master fura2\" class=\"rated-user user-orange\">fura2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 17:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122173\" href=\"?#comment-122173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4118\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is there any background in problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122173\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122203\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 21:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122203\" href=\"?#comment-122203\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122203\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122203\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 4rth q after so many TLE's I have drawn an inference that generally map is slower than set though both being dynamic memory allocation....</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122203 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122203 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122203\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122208\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122208\" href=\"?#comment-122208\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122208\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122208\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm quiet new in Java,I keep getting TLE and use trie data structure,any advises?(Though the same code written in C++ got AC) <a href=\"//codeforces.com/contest/271/submission/3109415\">code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122208 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122208 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122208\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122210\" commentParentId=\"122208\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122210\" href=\"?#comment-122210\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122208\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122210\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122210\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's not because you use Java, it's because you make a lot of substring() calls.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122210 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122210 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122210\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122211\" commentParentId=\"122210\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122211\" href=\"?#comment-122211\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122210\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122211\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122211\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks,so is there a faster way to remove the first character from string?Or i should use array of chars instead of strings or something like that</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122211 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122211 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122211\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122213\" commentParentId=\"122211\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122213\" href=\"?#comment-122213\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122211\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122213\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122213\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just remember where the string really begins.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122213 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122213 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122213\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122214\" commentParentId=\"122213\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122214\" href=\"?#comment-122214\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122213\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122214\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122214\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yup thanks got it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122214 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122214 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122214\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122525\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/syc0\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83057/avatar/3738e52d646e03e3.jpg'/> </a>\n <div><a href=\"/profile/syc0\" title=\"Pupil syc0\" class=\"rated-user user-green\">syc0</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 06:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122525\" href=\"?#comment-122525\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122525\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"83057\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122525\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i m not getting the problem E' editorial can any one explain ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122525 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122525 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122525\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"501419\" commentParentId=\"122525\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/23/2019 08:28\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-501419\" href=\"?#comment-501419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122525\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"501419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-501419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/6659?#comment-122056\">Here</a> is the proof for the solution given in the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-501419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-501419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-501419\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karthick\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/77362/avatar/2b6285094c5d5b71.jpg'/> </a>\n <div><a href=\"/profile/karthick\" title=\"Pupil karthick\" class=\"rated-user user-green\">karthick</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122591\" href=\"?#comment-122591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77362\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem 4, suffix array with lcp can also be used. We can first pre-compute the bad character count for all the substrings and store it in a table. Then, iterating through the suffix array and avoiding duplicate substrings using the lcp table, we can find the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122591\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122993\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122993\" href=\"?#comment-122993\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122993\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122993\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello. I am having trouble with the problem D (getting TLE). I am using the trie to solve the problem. When I build it, I already keep track of the current number of bad characters. If it is bigger than <em>k</em>, I leave the recursion. The final answer is the number of nodes of the tree.</p><p>Could anyone help me please? What am I doing wrong? <a href=\"//www.codeforces.com/contest/271/submission/3141412\">Code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122993 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122993 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122993\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122999\" commentParentId=\"122993\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/RAD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/397/avatar/8f89de4ecdba5051.jpg'/> </a>\n <div><a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122999\" href=\"?#comment-122999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122993\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why do you have these 2 nested loops in main() function? You are not really using <code>i</code> anywhere.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123013\" commentParentId=\"122999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 23:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123013\" href=\"?#comment-123013\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123013\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123013\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OMG, thanks RAD. It was something I was trying and forgot to remove.</p> <pre><code>for (int i = 0; i < n; ++i)\n{\n put(t, s + i);\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123013 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123013 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123013\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123094\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 07:39\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123094\" href=\"?#comment-123094\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123094\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123094\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C: in each set Ui, its elements ui, 1, ui, 2, ..., ui, |Ui| do not form an arithmetic progression (in particular, |Ui| ≥ 3 should hold). What's the meaning of it ? Does it means when Ui < 3 there is no necessary to hold this condition ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123094 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123094 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123094\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123097\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123097\" href=\"?#comment-123097\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123097\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123097\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you tell me what's wrong of my code ? Problem D: <a href=\"/contest/271/submission/3145554\" title=\"Submission 3145554 by water\">3145554</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123097 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123097 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123097\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123098\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:36\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123098\" href=\"?#comment-123098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Complexity</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123098\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123101\" commentParentId=\"123098\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123101\" href=\"?#comment-123101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123098\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think so, I learned from this AC submission? Why his is ok ? <a href=\"/contest/271/submission/3105181\" title=\"Submission 3105181 by a142857a\">3105181</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123102\" commentParentId=\"123101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 11:35\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123102\" href=\"?#comment-123102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try to find out what is the complexity of string comparisons</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123102\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"639472\" commentParentId=\"123102\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rudraksh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1170856/avatar/c5e36802b8507472.jpg'/> </a>\n <div><a href=\"/profile/Rudraksh\" title=\"Specialist Rudraksh\" class=\"rated-user user-cyan\">Rudraksh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2020 11:21\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-639472\" href=\"?#comment-639472\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123102\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"639472\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1170856\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-639472\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>so you're saying that insertion in set is taking time??</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-639472 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-639472 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-639472\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"661611\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/samarth9421\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/samarth9421\" title=\"Specialist samarth9421\" class=\"rated-user user-cyan\">samarth9421</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2020 20:07\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-661611\" href=\"?#comment-661611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"661611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1473183\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-661611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can implement it using sets but I think you have to iterate for len =1 to len=n and index 0 to n-len; after every len you have to clear your set to prevent it from exceeding memory limit</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-661611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-661611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-661611\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"366943\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ananth94\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/211746/avatar/72fbf14db6a1bcdc.jpg'/> </a>\n <div><a href=\"/profile/ananth94\" title=\"Specialist ananth94\" class=\"rated-user user-cyan\">ananth94</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2017 11:34\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-366943\" href=\"?#comment-366943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"366943\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"366943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"211746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-366943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D <a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a> : This is my code. I've used the concept of Rolling hash/Rabin Karp algorithm. But I guess there are some collisions happening and it's failing on test case number 8. Any help is greatly appreciated. Been trying this for a long time. </p><p>Code: <a href=\"/contest/271/submission/27820412\" title=\"Submission 27820412 by ananth94\">27820412</a></p><p>Update: Solved! I tried many different ways. Initially, I used two hash moduli instead of one, but this exceeded the Time Limit on test #8 (Which is weird!). I ended up using a really large prime (About the size of 2^50) which just passed the time limit for Testcase #8 and passed the cases as well. :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-366943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-366943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-366943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1037670\" commentParentId=\"366943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-VIBE\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2362415/avatar/7491393ac045f895.jpg'/> </a>\n <div><a href=\"/profile/-VIBE\" title=\"Expert -VIBE\" class=\"rated-user user-blue\">-VIBE</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2023 15:08\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1037670\" href=\"?#comment-1037670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-366943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1037670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2362415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1037670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya i was also getting wrong answer due to collisions so just used two different numbers 31 and 67 with modulo 1e9+7 and it got accepted </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1037670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1037670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1037670\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"466405\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingside\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingside\" title=\"Specialist kingside\" class=\"rated-user user-cyan\">kingside</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/24/2018 14:30\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-466405\" href=\"?#comment-466405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"466405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"378817\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-466405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D can be solved using 2 pointer and little bit of a lcp array.This is my solution. <a href=\"https://codeforces.com/contest/271/submission/44768791\">https://codeforces.com/contest/271/submission/44768791</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-466405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-466405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-466405\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"543325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aryan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/920094/avatar/c3ccd87908c923db.jpg'/> </a>\n <div><a href=\"/profile/aryan29\" title=\"Expert aryan29\" class=\"rated-user user-blue\">aryan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2019 23:23\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-543325\" href=\"?#comment-543325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"543325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"920094\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-543325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D is like using 2 hashes of 10^9 size-TLE Using 1hash of 10^9 size -WA and using a very big hash and multiplying recursive -TLE</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-543325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-543325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-543325\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arsalan9911\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1221235/avatar/7bd5179da6faa5e0.jpg'/> </a>\n <div><a href=\"/profile/arsalan9911\" title=\"Newbie arsalan9911\" class=\"rated-user user-gray\">arsalan9911</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 10:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552357\" href=\"?#comment-552357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"552357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1221235\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Beautiful Year</strong> <a href=\"https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year\">https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552368\" commentParentId=\"552357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 13:16\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552368\" href=\"?#comment-552368\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-552357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"552368\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"552368\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552368\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hey. Please stop spamming on every tutorial blog with your solutions of Div2 A problems. There are already many solutions available in the submissions section. You're not helping anyone at all. You're just spamming and also unnecessarily bringing old posts in the <strong>Recent Actions</strong> section.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552368 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552368 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552368\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"570233\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dsxv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/783201/avatar/b0756b3a28cbd94e.jpg'/> </a>\n <div><a href=\"/profile/Dsxv\" title=\"Expert Dsxv\" class=\"rated-user user-blue\">Dsxv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/03/2020 02:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-570233\" href=\"?#comment-570233\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"570233\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"783201\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-570233\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>271D using Z algorithm: <a href=\"https://codeforces.com/contest/271/submission/68098565\">https://codeforces.com/contest/271/submission/68098565</a></p><p>prereq: distinct substring using Z ( read it from CP algo ).</p><p>Implementation: Now I am assuming you know distinct substr using Z, then: we start counting the answer for a prefix after the zmax of that prefix. ( because we'll have distinct substring only after zmax)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-570233 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-570233 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-570233\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6721\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span 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Secret"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Secret</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The Greatest Secret Ever consists of <span class=\"tex-span\"><i>n</i></span> words, indexed by positive integers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. The secret needs dividing between <span class=\"tex-span\"><i>k</i></span> Keepers (let's index them by positive integers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>k</i></span>), the <span class=\"tex-span\"><i>i</i></span>-th Keeper gets a <span class=\"tex-font-style-bf\">non-empty</span> set of words with numbers from the set <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\"><i>i</i></sub> = (<i>u</i><sub class=\"lower-index\"><i>i</i>, 1</sub>, <i>u</i><sub class=\"lower-index\"><i>i</i>, 2</sub>, ..., <i>u</i><sub class=\"lower-index\"><i>i</i>, |<i>U</i><sub class=\"lower-index\"><i>i</i></sub>|</sub>)</span>. Here and below we'll presuppose that the set elements are written in the increasing order.</p><p>We'll say that the <span class=\"tex-font-style-it\">secret is safe</span> if the following conditions are hold:</p><ul> <li> for any two indexes <span class=\"tex-span\"><i>i</i>, <i>j</i></span> (<span class=\"tex-span\">1 ≤ <i>i</i> < <i>j</i> ≤ <i>k</i></span>) the intersection of sets <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\"><i>j</i></sub></span> is an empty set; </li><li> the union of sets <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\">1</sub>, <i>U</i><sub class=\"lower-index\">2</sub>, ..., <i>U</i><sub class=\"lower-index\"><i>k</i></sub></span> is set <span class=\"tex-span\">(1, 2, ..., <i>n</i>)</span>; </li><li> in each set <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\"><i>i</i></sub></span>, its elements <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i>, 1</sub>, <i>u</i><sub class=\"lower-index\"><i>i</i>, 2</sub>, ..., <i>u</i><sub class=\"lower-index\"><i>i</i>, |<i>U</i><sub class=\"lower-index\"><i>i</i></sub>|</sub></span> <span class=\"tex-font-style-bf\">do not form</span> an arithmetic progression (in particular, <span class=\"tex-span\">|<i>U</i><sub class=\"lower-index\"><i>i</i></sub>| ≥ 3</span> should hold). </li></ul><p>Let us remind you that the elements of set <span class=\"tex-span\">(<i>u</i><sub class=\"lower-index\">1</sub>, <i>u</i><sub class=\"lower-index\">2</sub>, ..., <i>u</i><sub class=\"lower-index\"><i>s</i></sub>)</span> form an arithmetic progression if there is such number <span class=\"tex-span\"><i>d</i></span>, that for all <span class=\"tex-span\"><i>i</i></span> (<span class=\"tex-span\">1 ≤ <i>i</i> < <i>s</i></span>) fulfills <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub> + <i>d</i> = <i>u</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>. For example, the elements of sets <span class=\"tex-span\">(5)</span>, <span class=\"tex-span\">(1, 10)</span> and <span class=\"tex-span\">(1, 5, 9)</span> form arithmetic progressions and the elements of sets <span class=\"tex-span\">(1, 2, 4)</span> and <span class=\"tex-span\">(3, 6, 8)</span> don't.</p><p>Your task is to find any partition of the set of words into subsets <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\">1</sub>, <i>U</i><sub class=\"lower-index\">2</sub>, ..., <i>U</i><sub class=\"lower-index\"><i>k</i></sub></span> so that the secret is safe. Otherwise indicate that there's no such partition.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input consists of a single line which contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">2 ≤ <i>k</i> ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the number of words in the secret and the number of the Keepers. The numbers are separated by a single space.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If there is no way to keep the secret safe, print a single integer \"-1\" (without the quotes). Otherwise, print <span class=\"tex-span\"><i>n</i></span> integers, the <span class=\"tex-span\"><i>i</i></span>-th of them representing the number of the Keeper who's got the <span class=\"tex-span\"><i>i</i></span>-th word of the secret.</p><p>If there are multiple solutions, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>11 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3 1 2 1 1 2 3 2 2 3 1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"14f57dc4dfae9c8e23826070e4275914\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"386e484be27a0ae7443e874543a82306c9570e72\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/271\">Codeforces Round 166 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/271/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Constructive algorithms\">\r\n constructive algorithms\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" 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\"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6659\" title=\"Codeforces Round #166 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1490:1491\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6662\" title=\"6662\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1489:21793\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/271\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/271/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/271/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/271/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/271/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/271/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/271/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/271/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_de258d9d532faafab63b150cdf10f437499274fb\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Secret</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The Greatest Secret Ever consists of <span class=\"tex-span\"><i>n</i></span> words, indexed by positive integers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>. The secret needs dividing between <span class=\"tex-span\"><i>k</i></span> Keepers (let's index them by positive integers from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>k</i></span>), the <span class=\"tex-span\"><i>i</i></span>-th Keeper gets a <span class=\"tex-font-style-bf\">non-empty</span> set of words with numbers from the set <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\"><i>i</i></sub> = (<i>u</i><sub class=\"lower-index\"><i>i</i>, 1</sub>, <i>u</i><sub class=\"lower-index\"><i>i</i>, 2</sub>, ..., <i>u</i><sub class=\"lower-index\"><i>i</i>, |<i>U</i><sub class=\"lower-index\"><i>i</i></sub>|</sub>)</span>. Here and below we'll presuppose that the set elements are written in the increasing order.</p><p>We'll say that the <span class=\"tex-font-style-it\">secret is safe</span> if the following conditions are hold:</p><ul> <li> for any two indexes <span class=\"tex-span\"><i>i</i>, <i>j</i></span> (<span class=\"tex-span\">1 ≤ <i>i</i> < <i>j</i> ≤ <i>k</i></span>) the intersection of sets <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\"><i>j</i></sub></span> is an empty set; </li><li> the union of sets <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\">1</sub>, <i>U</i><sub class=\"lower-index\">2</sub>, ..., <i>U</i><sub class=\"lower-index\"><i>k</i></sub></span> is set <span class=\"tex-span\">(1, 2, ..., <i>n</i>)</span>; </li><li> in each set <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\"><i>i</i></sub></span>, its elements <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i>, 1</sub>, <i>u</i><sub class=\"lower-index\"><i>i</i>, 2</sub>, ..., <i>u</i><sub class=\"lower-index\"><i>i</i>, |<i>U</i><sub class=\"lower-index\"><i>i</i></sub>|</sub></span> <span class=\"tex-font-style-bf\">do not form</span> an arithmetic progression (in particular, <span class=\"tex-span\">|<i>U</i><sub class=\"lower-index\"><i>i</i></sub>| ≥ 3</span> should hold). </li></ul><p>Let us remind you that the elements of set <span class=\"tex-span\">(<i>u</i><sub class=\"lower-index\">1</sub>, <i>u</i><sub class=\"lower-index\">2</sub>, ..., <i>u</i><sub class=\"lower-index\"><i>s</i></sub>)</span> form an arithmetic progression if there is such number <span class=\"tex-span\"><i>d</i></span>, that for all <span class=\"tex-span\"><i>i</i></span> (<span class=\"tex-span\">1 ≤ <i>i</i> < <i>s</i></span>) fulfills <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub> + <i>d</i> = <i>u</i><sub class=\"lower-index\"><i>i</i> + 1</sub></span>. For example, the elements of sets <span class=\"tex-span\">(5)</span>, <span class=\"tex-span\">(1, 10)</span> and <span class=\"tex-span\">(1, 5, 9)</span> form arithmetic progressions and the elements of sets <span class=\"tex-span\">(1, 2, 4)</span> and <span class=\"tex-span\">(3, 6, 8)</span> don't.</p><p>Your task is to find any partition of the set of words into subsets <span class=\"tex-span\"><i>U</i><sub class=\"lower-index\">1</sub>, <i>U</i><sub class=\"lower-index\">2</sub>, ..., <i>U</i><sub class=\"lower-index\"><i>k</i></sub></span> so that the secret is safe. Otherwise indicate that there's no such partition.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input consists of a single line which contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">2 ≤ <i>k</i> ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">6</sup></span>) — the number of words in the secret and the number of the Keepers. The numbers are separated by a single space.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If there is no way to keep the secret safe, print a single integer "-1" (without the quotes). Otherwise, print <span class=\"tex-span\"><i>n</i></span> integers, the <span class=\"tex-span\"><i>i</i></span>-th of them representing the number of the Keeper who's got the <span class=\"tex-span\"><i>i</i></span>-th word of the secret.</p><p>If there are multiple solutions, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>11 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3 1 2 1 1 2 3 2 2 3 1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='a1d4cd739c5a24c027443e72b228f37b'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/RAD\">RAD</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/RAD\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/RAD\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/RAD\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/RAD\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/RAD\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/RAD\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/RAD\" style=\"text-decoration:none;color:black !important;\">RAD's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6711\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6662\"> <p>Codeforces Round #166 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a>,\r\n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/271/problem/A\" title=\"Codeforces Round 166 (Div. 2)\">271A - Beautiful Year</a></p><p>This is a very straight forward problem. Just add 1 to a year number while it still has equal digits.</p><p><a href=\"/contest/271/problem/B\" title=\"Codeforces Round 166 (Div. 2)\">271B - Prime Matrix</a></p><p>Precalculate the next prime for every integer from <span class=\"tex-span\">1</span> to <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>. You can do that in any way. The main thing is to test all the divisors up to square root when you are checking if a number is prime.</p><p>Now for each <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> (element of the given matrix) we can easily calculate <span class=\"tex-span\"><i>add</i><sub class=\"lower-index\"><i>ij</i></sub></span> — how many do we have to add in order to make <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> prime. After that all we need to do is to find row or column with minimal sum in this new matrix.</p><p><a href=\"/contest/271/problem/C\" title=\"Codeforces Round 166 (Div. 2)\">271C - Secret</a></p><p>If <span class=\"tex-span\">3<i>k</i> > <i>n</i></span> there is no solution (because each of the <span class=\"tex-span\"><i>k</i></span> sets must have at least 3 elements). Otherwise we can divide first <span class=\"tex-span\">3<i>k</i></span> words in the following way:</p><p><code>1 1 2 2 3 3 ... k k 1 2 3 ... k</code></p><p>For each of the <span class=\"tex-span\"><i>k</i></span> sets, the difference between the first and the second elements will be <span class=\"tex-span\">1</span>. And the difference between the second and the third elements is definitely not <span class=\"tex-span\">1</span> (more precisely, it is <span class=\"tex-span\">2<i>k</i> - <i>i</i> - 1</span> for the <span class=\"tex-span\"><i>i</i></span>-th set). So each set doesn't form an arithmetic progression for sure.</p><p>For this solution it doesn't matter how we divide the rest <span class=\"tex-span\"><i>n</i> - 3<i>k</i></span> words.</p><p><a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a></p><p>At first, build a <a href=\"https://en.wikipedia.org/wiki/Trie\">trie</a> containing all suffixes of given string (this structure is also called explicit suffix tree). Let's iterate over all substrings in order of indexes' increasing, i. e. first <span class=\"tex-span\">[1...1], </span> then <span class=\"tex-span\">[1...2], [1...3], ..., [1...<i>n</i>], [2...2], [2...3], ..., [2...<i>n</i>], ...</span> Note, that moving from a substring to the next one is just adding a single character to the end. So we can easily maintain the number of bad characters, and also the "current" node in the trie. If the number of bad characters doesn't exceed <span class=\"tex-span\"><i>k</i></span>, then the substring is good. And we need to mark the corresponding node of trie, if we never did this before. The answer will be the number of marked nodes in the trie.</p><p>There is also an easier solution, where instead of trie we use <a href=\"https://en.wikipedia.org/wiki/Rolling_hash\">Rabin-Karp rolling hash</a> to count substrings that differ by content. Just sort the hashes of all good substrings and find the number of unique hashes (equal hashes will be on adjacent positions after sort). But these hashes are unreliable in general, so it's always better to use precise algorithm.</p><p><a href=\"/contest/271/problem/E\" title=\"Codeforces Round 166 (Div. 2)\">271E - Three Horses</a></p><p>It could be proved, that a card <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> <span class=\"tex-span\">(<i>x</i> < <i>y</i>)</span> can be transformed to any card <span class=\"tex-span\">(1, 1 + <i>k</i>·<i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is the maximal odd divisor of <span class=\"tex-span\"><i>y</i> - <i>x</i></span>, and <span class=\"tex-span\"><i>k</i></span> is just any positive integer. So every <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\"><i>i</i></sub> - 1)</span> must be divisible by <span class=\"tex-span\"><i>d</i></span>, i. e. <span class=\"tex-span\"><i>d</i></span> is a divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and we can just iterate over all possible divisors. Let's take a look at all the initial cards <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, which have have <span class=\"tex-span\"><i>d</i></span> as their maximal odd divisor: these are cards with <span class=\"tex-span\"><i>y</i> - <i>x</i></span> equal to <span class=\"tex-span\"><i>d</i></span>, or <span class=\"tex-span\">2<i>d</i></span>, or <span class=\"tex-span\">4<i>d</i></span>, <span class=\"tex-span\">8<i>d</i></span>, <span class=\"tex-span\">16<i>d</i></span>, ... Don't forget that the numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> must not exceed <span class=\"tex-span\"><i>m</i></span>. It means that the total number of cards with some fixed difference <span class=\"tex-span\"><i>t</i> = <i>y</i> - <i>x</i></span> is exactly <span class=\"tex-span\"><i>m</i> - <i>t</i></span>.</p><p>The resulting solution: sum up <span class=\"tex-span\">(<i>m</i> - 2<sup class=\"upper-index\"><i>l</i></sup><i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is any odd divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and <span class=\"tex-span\"><i>l</i></span> is such, that <span class=\"tex-span\">2<sup class=\"upper-index\"><i>l</i></sup><i>d</i> ≤ <i>m</i></span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/271\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 166 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-173-6711\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"173\",\n blogEntryId: \"6662\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces+round\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=166\" class=\"tag notice\" style=\"text-decoration: none;\">166</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+39</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/RAD\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/RAD\">\n RAD\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6662#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6662#comments\">\n 46\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6721\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (27)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122173\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fura2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4118/avatar/98f7ddceb1dac755.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/fura2\" title=\"Master fura2\" class=\"rated-user user-orange\">fura2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 17:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122173\" href=\"?#comment-122173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4118\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is there any background in problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122173\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122203\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 21:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122203\" href=\"?#comment-122203\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122203\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122203\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 4rth q after so many TLE's I have drawn an inference that generally map is slower than set though both being dynamic memory allocation....</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122203 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122203 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122203\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122208\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122208\" href=\"?#comment-122208\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122208\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122208\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm quiet new in Java,I keep getting TLE and use trie data structure,any advises?(Though the same code written in C++ got AC) <a href=\"//codeforces.com/contest/271/submission/3109415\">code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122208 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122208 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122208\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122210\" commentParentId=\"122208\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122210\" href=\"?#comment-122210\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122208\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122210\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122210\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's not because you use Java, it's because you make a lot of substring() calls.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122210 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122210 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122210\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122211\" commentParentId=\"122210\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122211\" href=\"?#comment-122211\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122210\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122211\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122211\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks,so is there a faster way to remove the first character from string?Or i should use array of chars instead of strings or something like that</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122211 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122211 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122211\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122213\" commentParentId=\"122211\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122213\" href=\"?#comment-122213\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122211\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122213\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122213\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just remember where the string really begins.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122213 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122213 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122213\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122214\" commentParentId=\"122213\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122214\" href=\"?#comment-122214\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122213\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122214\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122214\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yup thanks got it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122214 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122214 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122214\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122525\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/syc0\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83057/avatar/3738e52d646e03e3.jpg'/> </a>\n <div><a href=\"/profile/syc0\" title=\"Pupil syc0\" class=\"rated-user user-green\">syc0</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 06:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122525\" href=\"?#comment-122525\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122525\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"83057\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122525\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i m not getting the problem E' editorial can any one explain ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122525 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122525 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122525\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"501419\" commentParentId=\"122525\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/23/2019 08:28\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-501419\" href=\"?#comment-501419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122525\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"501419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-501419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/6659?#comment-122056\">Here</a> is the proof for the solution given in the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-501419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-501419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-501419\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karthick\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/77362/avatar/2b6285094c5d5b71.jpg'/> </a>\n <div><a href=\"/profile/karthick\" title=\"Pupil karthick\" class=\"rated-user user-green\">karthick</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122591\" href=\"?#comment-122591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77362\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem 4, suffix array with lcp can also be used. We can first pre-compute the bad character count for all the substrings and store it in a table. Then, iterating through the suffix array and avoiding duplicate substrings using the lcp table, we can find the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122591\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122993\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122993\" href=\"?#comment-122993\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122993\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122993\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello. I am having trouble with the problem D (getting TLE). I am using the trie to solve the problem. When I build it, I already keep track of the current number of bad characters. If it is bigger than <em>k</em>, I leave the recursion. The final answer is the number of nodes of the tree.</p><p>Could anyone help me please? What am I doing wrong? <a href=\"//www.codeforces.com/contest/271/submission/3141412\">Code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122993 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122993 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122993\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122999\" commentParentId=\"122993\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/RAD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/397/avatar/8f89de4ecdba5051.jpg'/> </a>\n <div><a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122999\" href=\"?#comment-122999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122993\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why do you have these 2 nested loops in main() function? You are not really using <code>i</code> anywhere.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123013\" commentParentId=\"122999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 23:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123013\" href=\"?#comment-123013\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123013\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123013\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OMG, thanks RAD. It was something I was trying and forgot to remove.</p> <pre><code>for (int i = 0; i < n; ++i)\n{\n put(t, s + i);\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123013 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123013 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123013\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123094\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 07:39\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123094\" href=\"?#comment-123094\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123094\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123094\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C: in each set Ui, its elements ui, 1, ui, 2, ..., ui, |Ui| do not form an arithmetic progression (in particular, |Ui| ≥ 3 should hold). What's the meaning of it ? Does it means when Ui < 3 there is no necessary to hold this condition ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123094 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123094 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123094\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123097\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123097\" href=\"?#comment-123097\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123097\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123097\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you tell me what's wrong of my code ? Problem D: <a href=\"/contest/271/submission/3145554\" title=\"Submission 3145554 by water\">3145554</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123097 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123097 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123097\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123098\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:36\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123098\" href=\"?#comment-123098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Complexity</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123098\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123101\" commentParentId=\"123098\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123101\" href=\"?#comment-123101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123098\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think so, I learned from this AC submission? Why his is ok ? <a href=\"/contest/271/submission/3105181\" title=\"Submission 3105181 by a142857a\">3105181</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123102\" commentParentId=\"123101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 11:35\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123102\" href=\"?#comment-123102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try to find out what is the complexity of string comparisons</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123102\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"639472\" commentParentId=\"123102\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rudraksh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1170856/avatar/c5e36802b8507472.jpg'/> </a>\n <div><a href=\"/profile/Rudraksh\" title=\"Specialist Rudraksh\" class=\"rated-user user-cyan\">Rudraksh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2020 11:21\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-639472\" href=\"?#comment-639472\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123102\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"639472\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1170856\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-639472\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>so you're saying that insertion in set is taking time??</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-639472 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-639472 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-639472\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"661611\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/samarth9421\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/samarth9421\" title=\"Specialist samarth9421\" class=\"rated-user user-cyan\">samarth9421</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2020 20:07\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-661611\" href=\"?#comment-661611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"661611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1473183\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-661611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can implement it using sets but I think you have to iterate for len =1 to len=n and index 0 to n-len; after every len you have to clear your set to prevent it from exceeding memory limit</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-661611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-661611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-661611\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"366943\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ananth94\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/211746/avatar/72fbf14db6a1bcdc.jpg'/> </a>\n <div><a href=\"/profile/ananth94\" title=\"Specialist ananth94\" class=\"rated-user user-cyan\">ananth94</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2017 11:34\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-366943\" href=\"?#comment-366943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"366943\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"366943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"211746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-366943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D <a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a> : This is my code. I've used the concept of Rolling hash/Rabin Karp algorithm. But I guess there are some collisions happening and it's failing on test case number 8. Any help is greatly appreciated. Been trying this for a long time. </p><p>Code: <a href=\"/contest/271/submission/27820412\" title=\"Submission 27820412 by ananth94\">27820412</a></p><p>Update: Solved! I tried many different ways. Initially, I used two hash moduli instead of one, but this exceeded the Time Limit on test #8 (Which is weird!). I ended up using a really large prime (About the size of 2^50) which just passed the time limit for Testcase #8 and passed the cases as well. :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-366943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-366943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-366943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1037670\" commentParentId=\"366943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-VIBE\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2362415/avatar/7491393ac045f895.jpg'/> </a>\n <div><a href=\"/profile/-VIBE\" title=\"Expert -VIBE\" class=\"rated-user user-blue\">-VIBE</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2023 15:08\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1037670\" href=\"?#comment-1037670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-366943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1037670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2362415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1037670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya i was also getting wrong answer due to collisions so just used two different numbers 31 and 67 with modulo 1e9+7 and it got accepted </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1037670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1037670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1037670\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"466405\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingside\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingside\" title=\"Specialist kingside\" class=\"rated-user user-cyan\">kingside</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/24/2018 14:30\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-466405\" href=\"?#comment-466405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"466405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"378817\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-466405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D can be solved using 2 pointer and little bit of a lcp array.This is my solution. <a href=\"https://codeforces.com/contest/271/submission/44768791\">https://codeforces.com/contest/271/submission/44768791</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-466405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-466405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-466405\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"543325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aryan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/920094/avatar/c3ccd87908c923db.jpg'/> </a>\n <div><a href=\"/profile/aryan29\" title=\"Expert aryan29\" class=\"rated-user user-blue\">aryan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2019 23:23\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-543325\" href=\"?#comment-543325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"543325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"920094\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-543325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D is like using 2 hashes of 10^9 size-TLE Using 1hash of 10^9 size -WA and using a very big hash and multiplying recursive -TLE</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-543325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-543325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-543325\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arsalan9911\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1221235/avatar/7bd5179da6faa5e0.jpg'/> </a>\n <div><a href=\"/profile/arsalan9911\" title=\"Newbie arsalan9911\" class=\"rated-user user-gray\">arsalan9911</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 10:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552357\" href=\"?#comment-552357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"552357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1221235\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Beautiful Year</strong> <a href=\"https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year\">https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552368\" commentParentId=\"552357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 13:16\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552368\" href=\"?#comment-552368\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-552357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"552368\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"552368\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552368\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hey. Please stop spamming on every tutorial blog with your solutions of Div2 A problems. There are already many solutions available in the submissions section. You're not helping anyone at all. You're just spamming and also unnecessarily bringing old posts in the <strong>Recent Actions</strong> section.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552368 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552368 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552368\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"570233\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dsxv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/783201/avatar/b0756b3a28cbd94e.jpg'/> </a>\n <div><a href=\"/profile/Dsxv\" title=\"Expert Dsxv\" class=\"rated-user user-blue\">Dsxv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/03/2020 02:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-570233\" href=\"?#comment-570233\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"570233\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"783201\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-570233\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>271D using Z algorithm: <a href=\"https://codeforces.com/contest/271/submission/68098565\">https://codeforces.com/contest/271/submission/68098565</a></p><p>prereq: distinct substring using Z ( read it from CP algo ).</p><p>Implementation: Now I am assuming you know distinct substr using Z, then: we start counting the answer for a prefix after the zmax of that prefix. ( because we'll have distinct substring only after zmax)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-570233 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-570233 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-570233\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6721\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span 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Good Substrings"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Good Substrings</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You've got string <span class=\"tex-span\"><i>s</i></span>, consisting of small English letters. Some of the English letters are <span class=\"tex-font-style-it\">good</span>, the rest are <span class=\"tex-font-style-it\">bad</span>.</p><p>A substring <span class=\"tex-span\"><i>s</i>[<i>l</i>...<i>r</i>]</span> (<span class=\"tex-span\">1 ≤ <i>l</i> ≤ <i>r</i> ≤ |<i>s</i>|</span>) of string <span class=\"tex-span\"><i>s</i> = <i>s</i><sub class=\"lower-index\">1</sub><i>s</i><sub class=\"lower-index\">2</sub>...<i>s</i><sub class=\"lower-index\">|<i>s</i>|</sub></span> (where <span class=\"tex-span\">|<i>s</i>|</span> is the length of string <span class=\"tex-span\"><i>s</i></span>) is string <span class=\"tex-span\"> <i>s</i><sub class=\"lower-index\"><i>l</i></sub><i>s</i><sub class=\"lower-index\"><i>l</i> + 1</sub>...<i>s</i><sub class=\"lower-index\"><i>r</i></sub></span>.</p><p>The substring <span class=\"tex-span\"><i>s</i>[<i>l</i>...<i>r</i>]</span> is <span class=\"tex-font-style-it\">good</span>, if among the letters <span class=\"tex-span\"> <i>s</i><sub class=\"lower-index\"><i>l</i></sub>, <i>s</i><sub class=\"lower-index\"><i>l</i> + 1</sub>, ..., <i>s</i><sub class=\"lower-index\"><i>r</i></sub></span> there are <span class=\"tex-font-style-bf\">at most</span> <span class=\"tex-span\"><i>k</i></span> <span class=\"tex-font-style-bf\">bad</span> ones (look at the sample's explanation to understand it more clear).</p><p>Your task is to find the number of distinct good substrings of the given string <span class=\"tex-span\"><i>s</i></span>. Two substrings <span class=\"tex-span\"><i>s</i>[<i>x</i>...<i>y</i>]</span> and <span class=\"tex-span\"><i>s</i>[<i>p</i>...<i>q</i>]</span> are considered distinct if their content is different, i.e. <span class=\"tex-span\"><i>s</i>[<i>x</i>...<i>y</i>] ≠ <i>s</i>[<i>p</i>...<i>q</i>]</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input is the non-empty string <span class=\"tex-span\"><i>s</i></span>, consisting of small English letters, the string's length is at most <span class=\"tex-span\">1500</span> characters.</p><p>The second line of the input is the string of characters \"<span class=\"tex-font-style-tt\">0</span>\" and \"<span class=\"tex-font-style-tt\">1</span>\", the length is exactly 26 characters. If the <span class=\"tex-span\"><i>i</i></span>-th character of this string equals \"<span class=\"tex-font-style-tt\">1</span>\", then the <span class=\"tex-span\"><i>i</i></span>-th English letter is good, otherwise it's bad. That is, the first character of this string corresponds to letter \"<span class=\"tex-font-style-tt\">a</span>\", the second one corresponds to letter \"<span class=\"tex-font-style-tt\">b</span>\" and so on.</p><p>The third line of the input consists a single integer <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">0 ≤ <i>k</i> ≤ |<i>s</i>|</span>) — the maximum acceptable number of bad characters in a good substring.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the number of distinct good substrings of string <span class=\"tex-span\"><i>s</i></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>ababab<br/>01000000000000000000000000<br/>1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>acbacbacaa<br/>00000000000000000000000000<br/>2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example there are following good substrings: \"<span class=\"tex-font-style-tt\">a</span>\", \"<span class=\"tex-font-style-tt\">ab</span>\", \"<span class=\"tex-font-style-tt\">b</span>\", \"<span class=\"tex-font-style-tt\">ba</span>\", \"<span class=\"tex-font-style-tt\">bab</span>\".</p><p>In the second example there are following good substrings: \"<span class=\"tex-font-style-tt\">a</span>\", \"<span class=\"tex-font-style-tt\">aa</span>\", \"<span class=\"tex-font-style-tt\">ac</span>\", \"<span class=\"tex-font-style-tt\">b</span>\", \"<span class=\"tex-font-style-tt\">ba</span>\", \"<span class=\"tex-font-style-tt\">c</span>\", \"<span class=\"tex-font-style-tt\">ca</span>\", \"<span class=\"tex-font-style-tt\">cb</span>\".</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"059fdf66a54477ecbde1220a2e61b230\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"386e484be27a0ae7443e874543a82306c9570e72\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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data-uuid=\"ps_7fed6c3895f7dca99b89e2f01376409a7801c5e6\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Good Substrings</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>512 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You've got string <span class=\"tex-span\"><i>s</i></span>, consisting of small English letters. Some of the English letters are <span class=\"tex-font-style-it\">good</span>, the rest are <span class=\"tex-font-style-it\">bad</span>.</p><p>A substring <span class=\"tex-span\"><i>s</i>[<i>l</i>...<i>r</i>]</span> (<span class=\"tex-span\">1 ≤ <i>l</i> ≤ <i>r</i> ≤ |<i>s</i>|</span>) of string <span class=\"tex-span\"><i>s</i> = <i>s</i><sub class=\"lower-index\">1</sub><i>s</i><sub class=\"lower-index\">2</sub>...<i>s</i><sub class=\"lower-index\">|<i>s</i>|</sub></span> (where <span class=\"tex-span\">|<i>s</i>|</span> is the length of string <span class=\"tex-span\"><i>s</i></span>) is string <span class=\"tex-span\"> <i>s</i><sub class=\"lower-index\"><i>l</i></sub><i>s</i><sub class=\"lower-index\"><i>l</i> + 1</sub>...<i>s</i><sub class=\"lower-index\"><i>r</i></sub></span>.</p><p>The substring <span class=\"tex-span\"><i>s</i>[<i>l</i>...<i>r</i>]</span> is <span class=\"tex-font-style-it\">good</span>, if among the letters <span class=\"tex-span\"> <i>s</i><sub class=\"lower-index\"><i>l</i></sub>, <i>s</i><sub class=\"lower-index\"><i>l</i> + 1</sub>, ..., <i>s</i><sub class=\"lower-index\"><i>r</i></sub></span> there are <span class=\"tex-font-style-bf\">at most</span> <span class=\"tex-span\"><i>k</i></span> <span class=\"tex-font-style-bf\">bad</span> ones (look at the sample's explanation to understand it more clear).</p><p>Your task is to find the number of distinct good substrings of the given string <span class=\"tex-span\"><i>s</i></span>. Two substrings <span class=\"tex-span\"><i>s</i>[<i>x</i>...<i>y</i>]</span> and <span class=\"tex-span\"><i>s</i>[<i>p</i>...<i>q</i>]</span> are considered distinct if their content is different, i.e. <span class=\"tex-span\"><i>s</i>[<i>x</i>...<i>y</i>] ≠ <i>s</i>[<i>p</i>...<i>q</i>]</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input is the non-empty string <span class=\"tex-span\"><i>s</i></span>, consisting of small English letters, the string's length is at most <span class=\"tex-span\">1500</span> characters.</p><p>The second line of the input is the string of characters "<span class=\"tex-font-style-tt\">0</span>" and "<span class=\"tex-font-style-tt\">1</span>", the length is exactly 26 characters. If the <span class=\"tex-span\"><i>i</i></span>-th character of this string equals "<span class=\"tex-font-style-tt\">1</span>", then the <span class=\"tex-span\"><i>i</i></span>-th English letter is good, otherwise it's bad. That is, the first character of this string corresponds to letter "<span class=\"tex-font-style-tt\">a</span>", the second one corresponds to letter "<span class=\"tex-font-style-tt\">b</span>" and so on.</p><p>The third line of the input consists a single integer <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">0 ≤ <i>k</i> ≤ |<i>s</i>|</span>) — the maximum acceptable number of bad characters in a good substring.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the number of distinct good substrings of string <span class=\"tex-span\"><i>s</i></span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>ababab<br />01000000000000000000000000<br />1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>5<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>acbacbacaa<br />00000000000000000000000000<br />2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first example there are following good substrings: "<span class=\"tex-font-style-tt\">a</span>", "<span class=\"tex-font-style-tt\">ab</span>", "<span class=\"tex-font-style-tt\">b</span>", "<span class=\"tex-font-style-tt\">ba</span>", "<span class=\"tex-font-style-tt\">bab</span>".</p><p>In the second example there are following good substrings: "<span class=\"tex-font-style-tt\">a</span>", "<span class=\"tex-font-style-tt\">aa</span>", "<span class=\"tex-font-style-tt\">ac</span>", "<span class=\"tex-font-style-tt\">b</span>", "<span class=\"tex-font-style-tt\">ba</span>", "<span class=\"tex-font-style-tt\">c</span>", "<span class=\"tex-font-style-tt\">ca</span>", "<span 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='a1d4cd739c5a24c027443e72b228f37b'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final 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style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/RAD\">RAD</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/RAD\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/RAD\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/RAD\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/RAD\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/RAD\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/RAD\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/RAD\" style=\"text-decoration:none;color:black !important;\">RAD's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6711\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6662\"> <p>Codeforces Round #166 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a>,\r\n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/271/problem/A\" title=\"Codeforces Round 166 (Div. 2)\">271A - Beautiful Year</a></p><p>This is a very straight forward problem. Just add 1 to a year number while it still has equal digits.</p><p><a href=\"/contest/271/problem/B\" title=\"Codeforces Round 166 (Div. 2)\">271B - Prime Matrix</a></p><p>Precalculate the next prime for every integer from <span class=\"tex-span\">1</span> to <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>. You can do that in any way. The main thing is to test all the divisors up to square root when you are checking if a number is prime.</p><p>Now for each <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> (element of the given matrix) we can easily calculate <span class=\"tex-span\"><i>add</i><sub class=\"lower-index\"><i>ij</i></sub></span> — how many do we have to add in order to make <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> prime. After that all we need to do is to find row or column with minimal sum in this new matrix.</p><p><a href=\"/contest/271/problem/C\" title=\"Codeforces Round 166 (Div. 2)\">271C - Secret</a></p><p>If <span class=\"tex-span\">3<i>k</i> > <i>n</i></span> there is no solution (because each of the <span class=\"tex-span\"><i>k</i></span> sets must have at least 3 elements). Otherwise we can divide first <span class=\"tex-span\">3<i>k</i></span> words in the following way:</p><p><code>1 1 2 2 3 3 ... k k 1 2 3 ... k</code></p><p>For each of the <span class=\"tex-span\"><i>k</i></span> sets, the difference between the first and the second elements will be <span class=\"tex-span\">1</span>. And the difference between the second and the third elements is definitely not <span class=\"tex-span\">1</span> (more precisely, it is <span class=\"tex-span\">2<i>k</i> - <i>i</i> - 1</span> for the <span class=\"tex-span\"><i>i</i></span>-th set). So each set doesn't form an arithmetic progression for sure.</p><p>For this solution it doesn't matter how we divide the rest <span class=\"tex-span\"><i>n</i> - 3<i>k</i></span> words.</p><p><a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a></p><p>At first, build a <a href=\"https://en.wikipedia.org/wiki/Trie\">trie</a> containing all suffixes of given string (this structure is also called explicit suffix tree). Let's iterate over all substrings in order of indexes' increasing, i. e. first <span class=\"tex-span\">[1...1], </span> then <span class=\"tex-span\">[1...2], [1...3], ..., [1...<i>n</i>], [2...2], [2...3], ..., [2...<i>n</i>], ...</span> Note, that moving from a substring to the next one is just adding a single character to the end. So we can easily maintain the number of bad characters, and also the "current" node in the trie. If the number of bad characters doesn't exceed <span class=\"tex-span\"><i>k</i></span>, then the substring is good. And we need to mark the corresponding node of trie, if we never did this before. The answer will be the number of marked nodes in the trie.</p><p>There is also an easier solution, where instead of trie we use <a href=\"https://en.wikipedia.org/wiki/Rolling_hash\">Rabin-Karp rolling hash</a> to count substrings that differ by content. Just sort the hashes of all good substrings and find the number of unique hashes (equal hashes will be on adjacent positions after sort). But these hashes are unreliable in general, so it's always better to use precise algorithm.</p><p><a href=\"/contest/271/problem/E\" title=\"Codeforces Round 166 (Div. 2)\">271E - Three Horses</a></p><p>It could be proved, that a card <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> <span class=\"tex-span\">(<i>x</i> < <i>y</i>)</span> can be transformed to any card <span class=\"tex-span\">(1, 1 + <i>k</i>·<i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is the maximal odd divisor of <span class=\"tex-span\"><i>y</i> - <i>x</i></span>, and <span class=\"tex-span\"><i>k</i></span> is just any positive integer. So every <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\"><i>i</i></sub> - 1)</span> must be divisible by <span class=\"tex-span\"><i>d</i></span>, i. e. <span class=\"tex-span\"><i>d</i></span> is a divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and we can just iterate over all possible divisors. Let's take a look at all the initial cards <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, which have have <span class=\"tex-span\"><i>d</i></span> as their maximal odd divisor: these are cards with <span class=\"tex-span\"><i>y</i> - <i>x</i></span> equal to <span class=\"tex-span\"><i>d</i></span>, or <span class=\"tex-span\">2<i>d</i></span>, or <span class=\"tex-span\">4<i>d</i></span>, <span class=\"tex-span\">8<i>d</i></span>, <span class=\"tex-span\">16<i>d</i></span>, ... Don't forget that the numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> must not exceed <span class=\"tex-span\"><i>m</i></span>. It means that the total number of cards with some fixed difference <span class=\"tex-span\"><i>t</i> = <i>y</i> - <i>x</i></span> is exactly <span class=\"tex-span\"><i>m</i> - <i>t</i></span>.</p><p>The resulting solution: sum up <span class=\"tex-span\">(<i>m</i> - 2<sup class=\"upper-index\"><i>l</i></sup><i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is any odd divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and <span class=\"tex-span\"><i>l</i></span> is such, that <span class=\"tex-span\">2<sup class=\"upper-index\"><i>l</i></sup><i>d</i> ≤ <i>m</i></span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/271\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 166 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-173-6711\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"173\",\n blogEntryId: \"6662\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces+round\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=166\" class=\"tag notice\" style=\"text-decoration: none;\">166</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+39</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/RAD\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/RAD\">\n RAD\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6662#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6662#comments\">\n 46\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6721\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (27)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122173\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fura2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4118/avatar/98f7ddceb1dac755.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/fura2\" title=\"Master fura2\" class=\"rated-user user-orange\">fura2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 17:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122173\" href=\"?#comment-122173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4118\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is there any background in problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122173\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122203\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 21:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122203\" href=\"?#comment-122203\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122203\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122203\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 4rth q after so many TLE's I have drawn an inference that generally map is slower than set though both being dynamic memory allocation....</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122203 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122203 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122203\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122208\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122208\" href=\"?#comment-122208\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122208\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122208\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm quiet new in Java,I keep getting TLE and use trie data structure,any advises?(Though the same code written in C++ got AC) <a href=\"//codeforces.com/contest/271/submission/3109415\">code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122208 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122208 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122208\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122210\" commentParentId=\"122208\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122210\" href=\"?#comment-122210\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122208\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122210\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122210\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's not because you use Java, it's because you make a lot of substring() calls.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122210 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122210 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122210\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122211\" commentParentId=\"122210\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122211\" href=\"?#comment-122211\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122210\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122211\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122211\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks,so is there a faster way to remove the first character from string?Or i should use array of chars instead of strings or something like that</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122211 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122211 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122211\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122213\" commentParentId=\"122211\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122213\" href=\"?#comment-122213\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122211\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122213\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122213\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just remember where the string really begins.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122213 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122213 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122213\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122214\" commentParentId=\"122213\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122214\" href=\"?#comment-122214\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122213\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122214\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122214\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yup thanks got it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122214 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122214 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122214\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122525\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/syc0\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83057/avatar/3738e52d646e03e3.jpg'/> </a>\n <div><a href=\"/profile/syc0\" title=\"Pupil syc0\" class=\"rated-user user-green\">syc0</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 06:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122525\" href=\"?#comment-122525\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122525\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"83057\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122525\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i m not getting the problem E' editorial can any one explain ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122525 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122525 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122525\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"501419\" commentParentId=\"122525\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/23/2019 08:28\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-501419\" href=\"?#comment-501419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122525\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"501419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-501419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/6659?#comment-122056\">Here</a> is the proof for the solution given in the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-501419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-501419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-501419\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karthick\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/77362/avatar/2b6285094c5d5b71.jpg'/> </a>\n <div><a href=\"/profile/karthick\" title=\"Pupil karthick\" class=\"rated-user user-green\">karthick</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122591\" href=\"?#comment-122591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77362\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem 4, suffix array with lcp can also be used. We can first pre-compute the bad character count for all the substrings and store it in a table. Then, iterating through the suffix array and avoiding duplicate substrings using the lcp table, we can find the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122591\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122993\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122993\" href=\"?#comment-122993\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122993\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122993\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello. I am having trouble with the problem D (getting TLE). I am using the trie to solve the problem. When I build it, I already keep track of the current number of bad characters. If it is bigger than <em>k</em>, I leave the recursion. The final answer is the number of nodes of the tree.</p><p>Could anyone help me please? What am I doing wrong? <a href=\"//www.codeforces.com/contest/271/submission/3141412\">Code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122993 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122993 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122993\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122999\" commentParentId=\"122993\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/RAD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/397/avatar/8f89de4ecdba5051.jpg'/> </a>\n <div><a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122999\" href=\"?#comment-122999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122993\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why do you have these 2 nested loops in main() function? You are not really using <code>i</code> anywhere.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123013\" commentParentId=\"122999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 23:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123013\" href=\"?#comment-123013\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123013\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123013\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OMG, thanks RAD. It was something I was trying and forgot to remove.</p> <pre><code>for (int i = 0; i < n; ++i)\n{\n put(t, s + i);\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123013 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123013 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123013\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123094\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 07:39\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123094\" href=\"?#comment-123094\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123094\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123094\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C: in each set Ui, its elements ui, 1, ui, 2, ..., ui, |Ui| do not form an arithmetic progression (in particular, |Ui| ≥ 3 should hold). What's the meaning of it ? Does it means when Ui < 3 there is no necessary to hold this condition ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123094 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123094 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123094\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123097\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123097\" href=\"?#comment-123097\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123097\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123097\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you tell me what's wrong of my code ? Problem D: <a href=\"/contest/271/submission/3145554\" title=\"Submission 3145554 by water\">3145554</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123097 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123097 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123097\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123098\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:36\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123098\" href=\"?#comment-123098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Complexity</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123098\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123101\" commentParentId=\"123098\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123101\" href=\"?#comment-123101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123098\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think so, I learned from this AC submission? Why his is ok ? <a href=\"/contest/271/submission/3105181\" title=\"Submission 3105181 by a142857a\">3105181</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123102\" commentParentId=\"123101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 11:35\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123102\" href=\"?#comment-123102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try to find out what is the complexity of string comparisons</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123102\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"639472\" commentParentId=\"123102\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rudraksh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1170856/avatar/c5e36802b8507472.jpg'/> </a>\n <div><a href=\"/profile/Rudraksh\" title=\"Specialist Rudraksh\" class=\"rated-user user-cyan\">Rudraksh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2020 11:21\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-639472\" href=\"?#comment-639472\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123102\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"639472\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1170856\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-639472\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>so you're saying that insertion in set is taking time??</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-639472 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-639472 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-639472\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"661611\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/samarth9421\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/samarth9421\" title=\"Specialist samarth9421\" class=\"rated-user user-cyan\">samarth9421</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2020 20:07\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-661611\" href=\"?#comment-661611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"661611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1473183\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-661611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can implement it using sets but I think you have to iterate for len =1 to len=n and index 0 to n-len; after every len you have to clear your set to prevent it from exceeding memory limit</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-661611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-661611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-661611\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"366943\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ananth94\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/211746/avatar/72fbf14db6a1bcdc.jpg'/> </a>\n <div><a href=\"/profile/ananth94\" title=\"Specialist ananth94\" class=\"rated-user user-cyan\">ananth94</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2017 11:34\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-366943\" href=\"?#comment-366943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"366943\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"366943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"211746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-366943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D <a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a> : This is my code. I've used the concept of Rolling hash/Rabin Karp algorithm. But I guess there are some collisions happening and it's failing on test case number 8. Any help is greatly appreciated. Been trying this for a long time. </p><p>Code: <a href=\"/contest/271/submission/27820412\" title=\"Submission 27820412 by ananth94\">27820412</a></p><p>Update: Solved! I tried many different ways. Initially, I used two hash moduli instead of one, but this exceeded the Time Limit on test #8 (Which is weird!). I ended up using a really large prime (About the size of 2^50) which just passed the time limit for Testcase #8 and passed the cases as well. :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-366943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-366943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-366943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1037670\" commentParentId=\"366943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-VIBE\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2362415/avatar/7491393ac045f895.jpg'/> </a>\n <div><a href=\"/profile/-VIBE\" title=\"Expert -VIBE\" class=\"rated-user user-blue\">-VIBE</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2023 15:08\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1037670\" href=\"?#comment-1037670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-366943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1037670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2362415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1037670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya i was also getting wrong answer due to collisions so just used two different numbers 31 and 67 with modulo 1e9+7 and it got accepted </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1037670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1037670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1037670\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"466405\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingside\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingside\" title=\"Specialist kingside\" class=\"rated-user user-cyan\">kingside</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/24/2018 14:30\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-466405\" href=\"?#comment-466405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"466405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"378817\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-466405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D can be solved using 2 pointer and little bit of a lcp array.This is my solution. <a href=\"https://codeforces.com/contest/271/submission/44768791\">https://codeforces.com/contest/271/submission/44768791</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-466405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-466405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-466405\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"543325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aryan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/920094/avatar/c3ccd87908c923db.jpg'/> </a>\n <div><a href=\"/profile/aryan29\" title=\"Expert aryan29\" class=\"rated-user user-blue\">aryan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2019 23:23\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-543325\" href=\"?#comment-543325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"543325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"920094\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-543325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D is like using 2 hashes of 10^9 size-TLE Using 1hash of 10^9 size -WA and using a very big hash and multiplying recursive -TLE</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-543325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-543325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-543325\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arsalan9911\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1221235/avatar/7bd5179da6faa5e0.jpg'/> </a>\n <div><a href=\"/profile/arsalan9911\" title=\"Newbie arsalan9911\" class=\"rated-user user-gray\">arsalan9911</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 10:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552357\" href=\"?#comment-552357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"552357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1221235\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Beautiful Year</strong> <a href=\"https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year\">https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552368\" commentParentId=\"552357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 13:16\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552368\" href=\"?#comment-552368\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-552357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"552368\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"552368\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552368\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hey. Please stop spamming on every tutorial blog with your solutions of Div2 A problems. There are already many solutions available in the submissions section. You're not helping anyone at all. You're just spamming and also unnecessarily bringing old posts in the <strong>Recent Actions</strong> section.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552368 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552368 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552368\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"570233\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dsxv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/783201/avatar/b0756b3a28cbd94e.jpg'/> </a>\n <div><a href=\"/profile/Dsxv\" title=\"Expert Dsxv\" class=\"rated-user user-blue\">Dsxv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/03/2020 02:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-570233\" href=\"?#comment-570233\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"570233\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"783201\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-570233\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>271D using Z algorithm: <a href=\"https://codeforces.com/contest/271/submission/68098565\">https://codeforces.com/contest/271/submission/68098565</a></p><p>prereq: distinct substring using Z ( read it from CP algo ).</p><p>Implementation: Now I am assuming you know distinct substr using Z, then: we start counting the answer for a prefix after the zmax of that prefix. ( because we'll have distinct substring only after zmax)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-570233 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-570233 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-570233\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6721\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span 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Three Horses"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Three Horses</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There are three horses living in a horse land: one gray, one white and one gray-and-white. The horses are really amusing animals, which is why they adore special cards. Each of those cards must contain two integers, the first one on top, the second one in the bottom of the card. Let's denote a card with <span class=\"tex-span\"><i>a</i></span> on the top and <span class=\"tex-span\"><i>b</i></span> in the bottom as <span class=\"tex-span\">(<i>a</i>, <i>b</i>)</span>.</p><p>Each of the three horses can paint the special cards. If you show an <span class=\"tex-span\">(<i>a</i>, <i>b</i>)</span> card to the gray horse, then the horse can paint a new <span class=\"tex-span\">(<i>a</i> + 1, <i>b</i> + 1)</span> card. If you show an <span class=\"tex-span\">(<i>a</i>, <i>b</i>)</span> card, such that <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> are even integers, to the white horse, then the horse can paint a new <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/192ec3678af0f5ba2aacda0740464256169e6b63.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> card. If you show two cards <span class=\"tex-span\">(<i>a</i>, <i>b</i>)</span> and <span class=\"tex-span\">(<i>b</i>, <i>c</i>)</span> to the gray-and-white horse, then he can paint a new <span class=\"tex-span\">(<i>a</i>, <i>c</i>)</span> card.</p><p>Polycarpus really wants to get <span class=\"tex-span\"><i>n</i></span> special cards <span class=\"tex-span\">(1, <i>a</i><sub class=\"lower-index\">1</sub>)</span>, <span class=\"tex-span\">(1, <i>a</i><sub class=\"lower-index\">2</sub>)</span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\">(1, <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. For that he is going to the horse land. He can take exactly one <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> card to the horse land, such that <span class=\"tex-span\">1 ≤ <i>x</i> < <i>y</i> ≤ <i>m</i></span>. How many ways are there to choose the card so that he can perform some actions in the horse land and get the required cards?</p><p>Polycarpus can get cards from the horses only as a result of the actions that are described above. Polycarpus is allowed to get additional cards besides the cards that he requires.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i>, <i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>, 2 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The second line contains the sequence of integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(2 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. Note, that the numbers in the sequence can coincide.</p><p>The numbers in the lines are separated by single spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to the problem. </p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in <span class=\"tex-font-style-it\">C++</span>. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 6<br/>2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>11<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 6<br/>7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>14<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 10<br/>13 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>36<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"cde4c18a1b06bad17d010d23eebfcd1a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"386e484be27a0ae7443e874543a82306c9570e72\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/271\">Codeforces Round 166 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/271/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Constructive algorithms\">\r\n constructive algorithms\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2200\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='cde4c18a1b06bad17d010d23eebfcd1a'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2621\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='cde4c18a1b06bad17d010d23eebfcd1a'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2621\"/>\r\n <input name=\"tagName\" 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-1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6662\" title=\"6662\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1489:21793\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/271\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/271/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/271/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/271/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/271/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/271/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/271/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/271/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_d5bb1ecf9254b6b6f8d56b7a48e87739adb3f682\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Three Horses</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There are three horses living in a horse land: one gray, one white and one gray-and-white. The horses are really amusing animals, which is why they adore special cards. Each of those cards must contain two integers, the first one on top, the second one in the bottom of the card. Let's denote a card with <span class=\"tex-span\"><i>a</i></span> on the top and <span class=\"tex-span\"><i>b</i></span> in the bottom as <span class=\"tex-span\">(<i>a</i>, <i>b</i>)</span>.</p><p>Each of the three horses can paint the special cards. If you show an <span class=\"tex-span\">(<i>a</i>, <i>b</i>)</span> card to the gray horse, then the horse can paint a new <span class=\"tex-span\">(<i>a</i> + 1, <i>b</i> + 1)</span> card. If you show an <span class=\"tex-span\">(<i>a</i>, <i>b</i>)</span> card, such that <span class=\"tex-span\"><i>a</i></span> and <span class=\"tex-span\"><i>b</i></span> are even integers, to the white horse, then the horse can paint a new <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/192ec3678af0f5ba2aacda0740464256169e6b63.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> card. If you show two cards <span class=\"tex-span\">(<i>a</i>, <i>b</i>)</span> and <span class=\"tex-span\">(<i>b</i>, <i>c</i>)</span> to the gray-and-white horse, then he can paint a new <span class=\"tex-span\">(<i>a</i>, <i>c</i>)</span> card.</p><p>Polycarpus really wants to get <span class=\"tex-span\"><i>n</i></span> special cards <span class=\"tex-span\">(1, <i>a</i><sub class=\"lower-index\">1</sub>)</span>, <span class=\"tex-span\">(1, <i>a</i><sub class=\"lower-index\">2</sub>)</span>, <span class=\"tex-span\">...</span>, <span class=\"tex-span\">(1, <i>a</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. For that he is going to the horse land. He can take exactly one <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> card to the horse land, such that <span class=\"tex-span\">1 ≤ <i>x</i> < <i>y</i> ≤ <i>m</i></span>. How many ways are there to choose the card so that he can perform some actions in the horse land and get the required cards?</p><p>Polycarpus can get cards from the horses only as a result of the actions that are described above. Polycarpus is allowed to get additional cards besides the cards that he requires.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i>, <i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>, 2 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The second line contains the sequence of integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(2 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. Note, that the numbers in the sequence can coincide.</p><p>The numbers in the lines are separated by single spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a single integer — the answer to the problem. </p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in <span class=\"tex-font-style-it\">C++</span>. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 6<br />2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>11<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 6<br />7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>14<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 10<br />13 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>36<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='a1d4cd739c5a24c027443e72b228f37b'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/RAD\">RAD</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/RAD\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/RAD\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/RAD\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/RAD\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/RAD\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/RAD\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/RAD\" style=\"text-decoration:none;color:black !important;\">RAD's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6711\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6662\"> <p>Codeforces Round #166 Tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a>,\r\n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/271/problem/A\" title=\"Codeforces Round 166 (Div. 2)\">271A - Beautiful Year</a></p><p>This is a very straight forward problem. Just add 1 to a year number while it still has equal digits.</p><p><a href=\"/contest/271/problem/B\" title=\"Codeforces Round 166 (Div. 2)\">271B - Prime Matrix</a></p><p>Precalculate the next prime for every integer from <span class=\"tex-span\">1</span> to <span class=\"tex-span\">10<sup class=\"upper-index\">5</sup></span>. You can do that in any way. The main thing is to test all the divisors up to square root when you are checking if a number is prime.</p><p>Now for each <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> (element of the given matrix) we can easily calculate <span class=\"tex-span\"><i>add</i><sub class=\"lower-index\"><i>ij</i></sub></span> — how many do we have to add in order to make <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> prime. After that all we need to do is to find row or column with minimal sum in this new matrix.</p><p><a href=\"/contest/271/problem/C\" title=\"Codeforces Round 166 (Div. 2)\">271C - Secret</a></p><p>If <span class=\"tex-span\">3<i>k</i> > <i>n</i></span> there is no solution (because each of the <span class=\"tex-span\"><i>k</i></span> sets must have at least 3 elements). Otherwise we can divide first <span class=\"tex-span\">3<i>k</i></span> words in the following way:</p><p><code>1 1 2 2 3 3 ... k k 1 2 3 ... k</code></p><p>For each of the <span class=\"tex-span\"><i>k</i></span> sets, the difference between the first and the second elements will be <span class=\"tex-span\">1</span>. And the difference between the second and the third elements is definitely not <span class=\"tex-span\">1</span> (more precisely, it is <span class=\"tex-span\">2<i>k</i> - <i>i</i> - 1</span> for the <span class=\"tex-span\"><i>i</i></span>-th set). So each set doesn't form an arithmetic progression for sure.</p><p>For this solution it doesn't matter how we divide the rest <span class=\"tex-span\"><i>n</i> - 3<i>k</i></span> words.</p><p><a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a></p><p>At first, build a <a href=\"https://en.wikipedia.org/wiki/Trie\">trie</a> containing all suffixes of given string (this structure is also called explicit suffix tree). Let's iterate over all substrings in order of indexes' increasing, i. e. first <span class=\"tex-span\">[1...1], </span> then <span class=\"tex-span\">[1...2], [1...3], ..., [1...<i>n</i>], [2...2], [2...3], ..., [2...<i>n</i>], ...</span> Note, that moving from a substring to the next one is just adding a single character to the end. So we can easily maintain the number of bad characters, and also the "current" node in the trie. If the number of bad characters doesn't exceed <span class=\"tex-span\"><i>k</i></span>, then the substring is good. And we need to mark the corresponding node of trie, if we never did this before. The answer will be the number of marked nodes in the trie.</p><p>There is also an easier solution, where instead of trie we use <a href=\"https://en.wikipedia.org/wiki/Rolling_hash\">Rabin-Karp rolling hash</a> to count substrings that differ by content. Just sort the hashes of all good substrings and find the number of unique hashes (equal hashes will be on adjacent positions after sort). But these hashes are unreliable in general, so it's always better to use precise algorithm.</p><p><a href=\"/contest/271/problem/E\" title=\"Codeforces Round 166 (Div. 2)\">271E - Three Horses</a></p><p>It could be proved, that a card <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span> <span class=\"tex-span\">(<i>x</i> < <i>y</i>)</span> can be transformed to any card <span class=\"tex-span\">(1, 1 + <i>k</i>·<i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is the maximal odd divisor of <span class=\"tex-span\"><i>y</i> - <i>x</i></span>, and <span class=\"tex-span\"><i>k</i></span> is just any positive integer. So every <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\"><i>i</i></sub> - 1)</span> must be divisible by <span class=\"tex-span\"><i>d</i></span>, i. e. <span class=\"tex-span\"><i>d</i></span> is a divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and we can just iterate over all possible divisors. Let's take a look at all the initial cards <span class=\"tex-span\">(<i>x</i>, <i>y</i>)</span>, which have have <span class=\"tex-span\"><i>d</i></span> as their maximal odd divisor: these are cards with <span class=\"tex-span\"><i>y</i> - <i>x</i></span> equal to <span class=\"tex-span\"><i>d</i></span>, or <span class=\"tex-span\">2<i>d</i></span>, or <span class=\"tex-span\">4<i>d</i></span>, <span class=\"tex-span\">8<i>d</i></span>, <span class=\"tex-span\">16<i>d</i></span>, ... Don't forget that the numbers <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> must not exceed <span class=\"tex-span\"><i>m</i></span>. It means that the total number of cards with some fixed difference <span class=\"tex-span\"><i>t</i> = <i>y</i> - <i>x</i></span> is exactly <span class=\"tex-span\"><i>m</i> - <i>t</i></span>.</p><p>The resulting solution: sum up <span class=\"tex-span\">(<i>m</i> - 2<sup class=\"upper-index\"><i>l</i></sup><i>d</i>)</span>, where <span class=\"tex-span\"><i>d</i></span> is any odd divisor of <span class=\"tex-span\"><i>gcd</i>(<i>a</i><sub class=\"lower-index\">1</sub> - 1, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub> - 1)</span>, and <span class=\"tex-span\"><i>l</i></span> is such, that <span class=\"tex-span\">2<sup class=\"upper-index\"><i>l</i></sup><i>d</i> ≤ <i>m</i></span>.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/271\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 166 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-173-6711\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"173\",\n blogEntryId: \"6662\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces+round\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=166\" class=\"tag notice\" style=\"text-decoration: none;\">166</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+39</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6711\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/RAD\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/RAD\">\n RAD\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/11/2013 21:55\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6662#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6662#comments\">\n 46\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6721\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (27)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122173\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/fura2\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4118/avatar/98f7ddceb1dac755.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/fura2\" title=\"Master fura2\" class=\"rated-user user-orange\">fura2</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 17:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122173\" href=\"?#comment-122173\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122173\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4118\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122173\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Is there any background in problem E?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122173 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122173 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122173\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122203\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/prakhar3agrwal\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45384/avatar/63c5e4d25f17da6b.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/prakhar3agrwal\" title=\"Expert prakhar3agrwal\" class=\"rated-user user-blue\">prakhar3agrwal</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 21:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122203\" href=\"?#comment-122203\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122203\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"45384\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122203\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In 4rth q after so many TLE's I have drawn an inference that generally map is slower than set though both being dynamic memory allocation....</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122203 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122203 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122203\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122208\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122208\" href=\"?#comment-122208\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122208\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122208\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I'm quiet new in Java,I keep getting TLE and use trie data structure,any advises?(Though the same code written in C++ got AC) <a href=\"//codeforces.com/contest/271/submission/3109415\">code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122208 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122208 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122208\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122210\" commentParentId=\"122208\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:52\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122210\" href=\"?#comment-122210\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122208\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122210\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122210\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It's not because you use Java, it's because you make a lot of substring() calls.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122210 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122210 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122210\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122211\" commentParentId=\"122210\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 22:58\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122211\" href=\"?#comment-122211\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122210\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122211\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122211\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks,so is there a faster way to remove the first character from string?Or i should use array of chars instead of strings or something like that</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122211 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122211 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122211\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122213\" commentParentId=\"122211\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:05\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122213\" href=\"?#comment-122213\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122211\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122213\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122213\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Just remember where the string really begins.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122213 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122213 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122213\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122214\" commentParentId=\"122213\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/filo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/32312/avatar/b7c41a22e80f9505.jpg'/> </a>\n <div><a href=\"/profile/filo\" title=\"Expert filo\" class=\"rated-user user-blue\">filo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2013 23:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122214\" href=\"?#comment-122214\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122213\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122214\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"32312\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122214\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Yup thanks got it</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122214 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122214 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122214\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122525\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/syc0\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/83057/avatar/3738e52d646e03e3.jpg'/> </a>\n <div><a href=\"/profile/syc0\" title=\"Pupil syc0\" class=\"rated-user user-green\">syc0</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 06:46\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122525\" href=\"?#comment-122525\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122525\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"83057\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122525\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>i m not getting the problem E' editorial can any one explain ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122525 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122525 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122525\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"501419\" commentParentId=\"122525\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/23/2019 08:28\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-501419\" href=\"?#comment-501419\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122525\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"501419\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-501419\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/6659?#comment-122056\">Here</a> is the proof for the solution given in the editorial.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-501419 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-501419 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-501419\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122591\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/karthick\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/77362/avatar/2b6285094c5d5b71.jpg'/> </a>\n <div><a href=\"/profile/karthick\" title=\"Pupil karthick\" class=\"rated-user user-green\">karthick</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122591\" href=\"?#comment-122591\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122591\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77362\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122591\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For problem 4, suffix array with lcp can also be used. We can first pre-compute the bad character count for all the substrings and store it in a table. Then, iterating through the suffix array and avoiding duplicate substrings using the lcp table, we can find the answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122591 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122591 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122591\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122993\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:19\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122993\" href=\"?#comment-122993\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122993\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122993\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hello. I am having trouble with the problem D (getting TLE). I am using the trie to solve the problem. When I build it, I already keep track of the current number of bad characters. If it is bigger than <em>k</em>, I leave the recursion. The final answer is the number of nodes of the tree.</p><p>Could anyone help me please? What am I doing wrong? <a href=\"//www.codeforces.com/contest/271/submission/3141412\">Code</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122993 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122993 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122993\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122999\" commentParentId=\"122993\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/RAD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/397/avatar/8f89de4ecdba5051.jpg'/> </a>\n <div><a href=\"/profile/RAD\" title=\"Grandmaster RAD\" class=\"rated-user user-red\">RAD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122999\" href=\"?#comment-122999\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122993\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122999\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122999\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"397\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122999\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why do you have these 2 nested loops in main() function? You are not really using <code>i</code> anywhere.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122999 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122999 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122999\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123013\" commentParentId=\"122999\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/LucasJA\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/45804/avatar/c7baf9eede005ef2.jpg'/> </a>\n <div><a href=\"/profile/LucasJA\" title=\"Expert LucasJA\" class=\"rated-user user-blue\">LucasJA</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 23:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123013\" href=\"?#comment-123013\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122999\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123013\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"45804\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123013\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>OMG, thanks RAD. It was something I was trying and forgot to remove.</p> <pre><code>for (int i = 0; i < n; ++i)\n{\n put(t, s + i);\n}\n</code></pre></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123013 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123013 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123013\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123094\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 07:39\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123094\" href=\"?#comment-123094\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123094\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123094\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem C: in each set Ui, its elements ui, 1, ui, 2, ..., ui, |Ui| do not form an arithmetic progression (in particular, |Ui| ≥ 3 should hold). What's the meaning of it ? Does it means when Ui < 3 there is no necessary to hold this condition ?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123094 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123094 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123094\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123097\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:26\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123097\" href=\"?#comment-123097\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123097\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123097\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can you tell me what's wrong of my code ? Problem D: <a href=\"/contest/271/submission/3145554\" title=\"Submission 3145554 by water\">3145554</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123097 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123097 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123097\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123098\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:36\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123098\" href=\"?#comment-123098\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123098\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123098\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Complexity</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123098 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123098 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123098\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123101\" commentParentId=\"123098\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/water\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/35536/avatar/f12f4e5cca2021ca.jpg'/> </a>\n <div><a href=\"/profile/water\" title=\"Newbie water\" class=\"rated-user user-gray\">water</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 10:48\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123101\" href=\"?#comment-123101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123098\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"35536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't think so, I learned from this AC submission? Why his is ok ? <a href=\"/contest/271/submission/3105181\" title=\"Submission 3105181 by a142857a\">3105181</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123102\" commentParentId=\"123101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/dalex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/4200/avatar/fe9bfc44be854399.jpg'/> </a>\n <div><a href=\"/profile/dalex\" title=\"Master dalex\" class=\"rated-user user-orange\">dalex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/19/2013 11:35\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123102\" href=\"?#comment-123102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4200\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Try to find out what is the complexity of string comparisons</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123102\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"639472\" commentParentId=\"123102\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rudraksh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1170856/avatar/c5e36802b8507472.jpg'/> </a>\n <div><a href=\"/profile/Rudraksh\" title=\"Specialist Rudraksh\" class=\"rated-user user-cyan\">Rudraksh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2020 11:21\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-639472\" href=\"?#comment-639472\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123102\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"639472\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1170856\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-639472\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>so you're saying that insertion in set is taking time??</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-639472 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-639472 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-639472\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"661611\" commentParentId=\"123097\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/samarth9421\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/samarth9421\" title=\"Specialist samarth9421\" class=\"rated-user user-cyan\">samarth9421</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/13/2020 20:07\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-661611\" href=\"?#comment-661611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123097\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"661611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1473183\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-661611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>You can implement it using sets but I think you have to iterate for len =1 to len=n and index 0 to n-len; after every len you have to clear your set to prevent it from exceeding memory limit</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-661611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-661611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-661611\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"366943\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/ananth94\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/211746/avatar/72fbf14db6a1bcdc.jpg'/> </a>\n <div><a href=\"/profile/ananth94\" title=\"Specialist ananth94\" class=\"rated-user user-cyan\">ananth94</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2017 11:34\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-366943\" href=\"?#comment-366943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"366943\" revisionCount=\"4\" revision=\"4\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">4</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"366943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"211746\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-366943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D <a href=\"/contest/271/problem/D\" title=\"Codeforces Round 166 (Div. 2)\">271D - Good Substrings</a> : This is my code. I've used the concept of Rolling hash/Rabin Karp algorithm. But I guess there are some collisions happening and it's failing on test case number 8. Any help is greatly appreciated. Been trying this for a long time. </p><p>Code: <a href=\"/contest/271/submission/27820412\" title=\"Submission 27820412 by ananth94\">27820412</a></p><p>Update: Solved! I tried many different ways. Initially, I used two hash moduli instead of one, but this exceeded the Time Limit on test #8 (Which is weird!). I ended up using a really large prime (About the size of 2^50) which just passed the time limit for Testcase #8 and passed the cases as well. :) </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-366943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-366943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-366943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1037670\" commentParentId=\"366943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/-VIBE\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2362415/avatar/7491393ac045f895.jpg'/> </a>\n <div><a href=\"/profile/-VIBE\" title=\"Expert -VIBE\" class=\"rated-user user-blue\">-VIBE</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/16/2023 15:08\">4 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1037670\" href=\"?#comment-1037670\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-366943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1037670\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2362415\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1037670\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya i was also getting wrong answer due to collisions so just used two different numbers 31 and 67 with modulo 1e9+7 and it got accepted </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1037670 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1037670 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-1037670\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"466405\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/kingside\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/kingside\" title=\"Specialist kingside\" class=\"rated-user user-cyan\">kingside</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/24/2018 14:30\">5 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-466405\" href=\"?#comment-466405\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"466405\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"378817\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-466405\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>D can be solved using 2 pointer and little bit of a lcp array.This is my solution. <a href=\"https://codeforces.com/contest/271/submission/44768791\">https://codeforces.com/contest/271/submission/44768791</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-466405 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-466405 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-466405\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"543325\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aryan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/920094/avatar/c3ccd87908c923db.jpg'/> </a>\n <div><a href=\"/profile/aryan29\" title=\"Expert aryan29\" class=\"rated-user user-blue\">aryan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2019 23:23\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-543325\" href=\"?#comment-543325\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"543325\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"920094\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-543325\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Problem D is like using 2 hashes of 10^9 size-TLE Using 1hash of 10^9 size -WA and using a very big hash and multiplying recursive -TLE</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-543325 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-543325 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-543325\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/arsalan9911\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1221235/avatar/7bd5179da6faa5e0.jpg'/> </a>\n <div><a href=\"/profile/arsalan9911\" title=\"Newbie arsalan9911\" class=\"rated-user user-gray\">arsalan9911</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 10:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552357\" href=\"?#comment-552357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"552357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1221235\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><strong>Beautiful Year</strong> <a href=\"https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year\">https://github.com/arsalanhub/CodeForces/blob/master/Beautiful%20Year</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"552368\" commentParentId=\"552357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Oct/21/2019 13:16\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-552368\" href=\"?#comment-552368\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-552357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"552368\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"552368\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-552368\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Hey. Please stop spamming on every tutorial blog with your solutions of Div2 A problems. There are already many solutions available in the submissions section. You're not helping anyone at all. You're just spamming and also unnecessarily bringing old posts in the <strong>Recent Actions</strong> section.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-552368 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-552368 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-552368\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"570233\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Dsxv\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/783201/avatar/b0756b3a28cbd94e.jpg'/> </a>\n <div><a href=\"/profile/Dsxv\" title=\"Expert Dsxv\" class=\"rated-user user-blue\">Dsxv</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/03/2020 02:33\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-570233\" href=\"?#comment-570233\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"570233\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"783201\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-570233\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>271D using Z algorithm: <a href=\"https://codeforces.com/contest/271/submission/68098565\">https://codeforces.com/contest/271/submission/68098565</a></p><p>prereq: distinct substring using Z ( read it from CP algo ).</p><p>Implementation: Now I am assuming you know distinct substr using Z, then: we start counting the answer for a prefix after the zmax of that prefix. ( because we'll have distinct substring only after zmax)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-570233 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-570233 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-570233\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-6721\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span 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Dima and Friends"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Dima and Friends</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima and his friends have been playing hide and seek at Dima's place all night. As a result, Dima's place got messy. In the morning they decided that they need to clean the place.</p><p>To decide who exactly would clean the apartment, the friends want to play a counting-out game. First, all the guys stand in a circle, and then each of them shows some number of fingers on one hand (one to five), and then the boys count in a circle, starting from Dima, the number of people, respective to the total number of fingers shown. The person on who the countdown stops will clean the apartment.</p><p>For example, if Dima and one of his friends played hide and seek, and <span class=\"tex-span\">7</span> fingers were shown during the counting-out, then Dima would clean the place. If there were <span class=\"tex-span\">2</span> or say, <span class=\"tex-span\">8</span> fingers shown, then his friend would clean the place.</p><p>Dima knows how many fingers each of his friends will show during the counting-out. Now he is interested in the number of ways to show some number of fingers on one hand (one to five), so that he did not have to clean the place. Help Dima.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 100)</span> — the number of Dima's friends. Dima himself isn't considered to be his own friend. The second line contains <span class=\"tex-span\"><i>n</i></span> positive integers, not exceeding <span class=\"tex-span\">5</span>, representing, how many fingers the Dima's friends will show. </p><p>The numbers in the lines are separated by a single space.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>3 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample Dima can show <span class=\"tex-span\">1</span>, <span class=\"tex-span\">3</span> or <span class=\"tex-span\">5</span> fingers. If Dima shows <span class=\"tex-span\">3</span> fingers, then the counting-out will go like that: Dima, his friend, Dima, his friend.</p><p>In the second sample Dima can show <span class=\"tex-span\">2</span> or <span class=\"tex-span\">4</span> fingers.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"842539f59a477477b863386b9587ff19\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e09ff796b44559e049aa751f6da398be96cbe0e6\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/272\">Codeforces Round 167 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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</div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='842539f59a477477b863386b9587ff19'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2622\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='842539f59a477477b863386b9587ff19'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2622\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm 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Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6677\" title=\"Codeforces Round #167\" target=\"_blank\">Codeforces Round #167</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1494:1495\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6625\" title=\"Codeforces Round #167 tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1736:1737\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/272\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/272/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/272/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/272/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/272/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/272/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/272/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/272/customtest\">Custom 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result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_6634a814a077d997807cc382a5fdb97fa91dc2c5\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Dima and Friends</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima and his friends have been playing hide and seek at Dima's place all night. As a result, Dima's place got messy. In the morning they decided that they need to clean the place.</p><p>To decide who exactly would clean the apartment, the friends want to play a counting-out game. First, all the guys stand in a circle, and then each of them shows some number of fingers on one hand (one to five), and then the boys count in a circle, starting from Dima, the number of people, respective to the total number of fingers shown. The person on who the countdown stops will clean the apartment.</p><p>For example, if Dima and one of his friends played hide and seek, and <span class=\"tex-span\">7</span> fingers were shown during the counting-out, then Dima would clean the place. If there were <span class=\"tex-span\">2</span> or say, <span class=\"tex-span\">8</span> fingers shown, then his friend would clean the place.</p><p>Dima knows how many fingers each of his friends will show during the counting-out. Now he is interested in the number of ways to show some number of fingers on one hand (one to five), so that he did not have to clean the place. Help Dima.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 100)</span> — the number of Dima's friends. Dima himself isn't considered to be his own friend. The second line contains <span class=\"tex-span\"><i>n</i></span> positive integers, not exceeding <span class=\"tex-span\">5</span>, representing, how many fingers the Dima's friends will show. </p><p>The numbers in the lines are separated by a single space.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />3 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample Dima can show <span class=\"tex-span\">1</span>, <span class=\"tex-span\">3</span> or <span class=\"tex-span\">5</span> fingers. If Dima shows <span class=\"tex-span\">3</span> fingers, then the counting-out will go like that: Dima, his friend, Dima, his friend.</p><p>In the second sample Dima can show <span class=\"tex-span\">2</span> or <span class=\"tex-span\">4</span> fingers.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Sequence"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Dima and Sequence</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima got into number sequences. Now he's got sequence <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, consisting of <span class=\"tex-span\"><i>n</i></span> positive integers. Also, Dima has got a function <span class=\"tex-span\"><i>f</i>(<i>x</i>)</span>, which can be defined with the following recurrence:</p><ul> <li> <span class=\"tex-span\"><i>f</i>(0) = 0</span>; </li><li> <span class=\"tex-span\"><i>f</i>(2·<i>x</i>) = <i>f</i>(<i>x</i>)</span>; </li><li> <span class=\"tex-span\"><i>f</i>(2·<i>x</i> + 1) = <i>f</i>(<i>x</i>) + 1</span>. </li></ul><p>Dima wonders, how many pairs of indexes <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> <span class=\"tex-span\">(1 ≤ <i>i</i> < <i>j</i> ≤ <i>n</i>)</span> are there, such that <span class=\"tex-span\"><i>f</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>f</i>(<i>a</i><sub class=\"lower-index\"><i>j</i></sub>)</span>. Help him, count the number of such pairs. </p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> positive integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>.</p><p>The numbers in the lines are separated by single spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the answer to the problem.</p><p>Please, don't use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in <span class=\"tex-font-style-it\">C++</span>. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>1 2 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>5 3 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample any pair <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> will do, so the answer is <span class=\"tex-span\">3</span>.</p><p>In the second sample only pair <span class=\"tex-span\">(1, 2)</span> will do.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"c246474021590700a1e23199d53b2a84\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e09ff796b44559e049aa751f6da398be96cbe0e6\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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data-uuid=\"ps_551b5b071b46d330f4e9ecdfb8733038419d5532\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Dima and Sequence</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima got into number sequences. Now he's got sequence <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>, consisting of <span class=\"tex-span\"><i>n</i></span> positive integers. Also, Dima has got a function <span class=\"tex-span\"><i>f</i>(<i>x</i>)</span>, which can be defined with the following recurrence:</p><ul> <li> <span class=\"tex-span\"><i>f</i>(0) = 0</span>; </li><li> <span class=\"tex-span\"><i>f</i>(2·<i>x</i>) = <i>f</i>(<i>x</i>)</span>; </li><li> <span class=\"tex-span\"><i>f</i>(2·<i>x</i> + 1) = <i>f</i>(<i>x</i>) + 1</span>. </li></ul><p>Dima wonders, how many pairs of indexes <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> <span class=\"tex-span\">(1 ≤ <i>i</i> < <i>j</i> ≤ <i>n</i>)</span> are there, such that <span class=\"tex-span\"><i>f</i>(<i>a</i><sub class=\"lower-index\"><i>i</i></sub>) = <i>f</i>(<i>a</i><sub class=\"lower-index\"><i>j</i></sub>)</span>. Help him, count the number of such pairs. </p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> positive integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>.</p><p>The numbers in the lines are separated by single spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the answer to the problem.</p><p>Please, don't use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in <span class=\"tex-font-style-it\">C++</span>. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />1 2 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />5 3 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample any pair <span class=\"tex-span\">(<i>i</i>, <i>j</i>)</span> will do, so the answer is <span class=\"tex-span\">3</span>.</p><p>In the second sample only pair <span class=\"tex-span\">(1, 2)</span> will do.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final 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style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Staircase"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Dima and Staircase</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima's got a staircase that consists of <span class=\"tex-span\"><i>n</i></span> stairs. The first stair is at height <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, the second one is at <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, the last one is at <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\">1</sub> ≤ <i>a</i><sub class=\"lower-index\">2</sub> ≤ ... ≤ <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>). </p><p>Dima decided to play with the staircase, so he is throwing rectangular boxes at the staircase from above. The <span class=\"tex-span\"><i>i</i></span>-th box has width <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> and height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>. Dima throws each box vertically down on the first <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> stairs of the staircase, that is, the box covers stairs with numbers <span class=\"tex-span\">1, 2, ..., <i>w</i><sub class=\"lower-index\"><i>i</i></sub></span>. Each thrown box flies vertically down until at least one of the two following events happen:</p><ul> <li> the bottom of the box touches the top of a stair; </li><li> the bottom of the box touches the top of a box, thrown earlier. </li></ul><p>We only consider touching of the horizontal sides of stairs and boxes, at that touching with the corners isn't taken into consideration. Specifically, that implies that a box with width <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> cannot touch the stair number <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub> + 1</span>.</p><p>You are given the description of the staircase and the sequence in which Dima threw the boxes at it. For each box, determine how high the bottom of the box after landing will be. Consider a box to fall after the previous one lands.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of stairs in the staircase. The second line contains a non-decreasing sequence, consisting of <span class=\"tex-span\"><i>n</i></span> integers, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub>)</span>.</p><p>The next line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of boxes. Each of the following <span class=\"tex-span\"><i>m</i></span> lines contains a pair of integers <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub>, <i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>w</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>; 1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span> — the size of the <span class=\"tex-span\"><i>i</i></span>-th thrown box.</p><p>The numbers in the lines are separated by spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-span\"><i>m</i></span> integers — for each box the height, where the bottom of the box will be after landing. Print the answers for the boxes in the order, in which the boxes are given in the input.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in <span class=\"tex-font-style-it\">C++</span>. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>1 2 3 6 6<br/>4<br/>1 1<br/>3 1<br/>1 1<br/>4 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>3<br/>4<br/>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>1 2 3<br/>2<br/>1 1<br/>3 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>1<br/>5<br/>1 2<br/>1 10<br/>1 10<br/>1 10<br/>1 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>3<br/>13<br/>23<br/>33<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first sample are shown on the picture.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/26b9c4700d78041bb0da712cc0530f4b16d7ec8f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"c5dfcdd58272e2c80444cd07c2c728c4\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e09ff796b44559e049aa751f6da398be96cbe0e6\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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data-uuid=\"ps_8e79a6ebe6ee53b923aa6754a348f58b738939e2\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Dima and Staircase</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima's got a staircase that consists of <span class=\"tex-span\"><i>n</i></span> stairs. The first stair is at height <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, the second one is at <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, the last one is at <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\">1</sub> ≤ <i>a</i><sub class=\"lower-index\">2</sub> ≤ ... ≤ <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>). </p><p>Dima decided to play with the staircase, so he is throwing rectangular boxes at the staircase from above. The <span class=\"tex-span\"><i>i</i></span>-th box has width <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> and height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>. Dima throws each box vertically down on the first <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> stairs of the staircase, that is, the box covers stairs with numbers <span class=\"tex-span\">1, 2, ..., <i>w</i><sub class=\"lower-index\"><i>i</i></sub></span>. Each thrown box flies vertically down until at least one of the two following events happen:</p><ul> <li> the bottom of the box touches the top of a stair; </li><li> the bottom of the box touches the top of a box, thrown earlier. </li></ul><p>We only consider touching of the horizontal sides of stairs and boxes, at that touching with the corners isn't taken into consideration. Specifically, that implies that a box with width <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> cannot touch the stair number <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub> + 1</span>.</p><p>You are given the description of the staircase and the sequence in which Dima threw the boxes at it. For each box, determine how high the bottom of the box after landing will be. Consider a box to fall after the previous one lands.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of stairs in the staircase. The second line contains a non-decreasing sequence, consisting of <span class=\"tex-span\"><i>n</i></span> integers, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub>)</span>.</p><p>The next line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of boxes. Each of the following <span class=\"tex-span\"><i>m</i></span> lines contains a pair of integers <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub>, <i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>w</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>; 1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span> — the size of the <span class=\"tex-span\"><i>i</i></span>-th thrown box.</p><p>The numbers in the lines are separated by spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-span\"><i>m</i></span> integers — for each box the height, where the bottom of the box will be after landing. Print the answers for the boxes in the order, in which the boxes are given in the input.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in <span class=\"tex-font-style-it\">C++</span>. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />1 2 3 6 6<br />4<br />1 1<br />3 1<br />1 1<br />4 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />3<br />4<br />6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />1 2 3<br />2<br />1 1<br />3 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />1<br />5<br />1 2<br />1 10<br />1 10<br />1 10<br />1 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />3<br />13<br />23<br />33<br /></pre></div></div></div><div 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Two Sequences"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Dima and Two Sequences</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Little Dima has two sequences of points with integer coordinates: sequence <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\">1</sub>, 1), (<i>a</i><sub class=\"lower-index\">2</sub>, 2), ..., (<i>a</i><sub class=\"lower-index\"><i>n</i></sub>, <i>n</i>)</span> and sequence <span class=\"tex-span\">(<i>b</i><sub class=\"lower-index\">1</sub>, 1), (<i>b</i><sub class=\"lower-index\">2</sub>, 2), ..., (<i>b</i><sub class=\"lower-index\"><i>n</i></sub>, <i>n</i>)</span>.</p><p>Now Dima wants to count the number of distinct sequences of points of length <span class=\"tex-span\">2·<i>n</i></span> that can be assembled from these sequences, such that the <span class=\"tex-span\"><i>x</i></span>-coordinates of points in the assembled sequence will <span class=\"tex-font-style-bf\">not decrease</span>. Help him with that. Note that each element of the initial sequences should be used exactly once in the assembled sequence.</p><p>Dima considers two assembled sequences <span class=\"tex-span\">(<i>p</i><sub class=\"lower-index\">1</sub>, <i>q</i><sub class=\"lower-index\">1</sub>), (<i>p</i><sub class=\"lower-index\">2</sub>, <i>q</i><sub class=\"lower-index\">2</sub>), ..., (<i>p</i><sub class=\"lower-index\">2·<i>n</i></sub>, <i>q</i><sub class=\"lower-index\">2·<i>n</i></sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>), (<i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>), ..., (<i>x</i><sub class=\"lower-index\">2·<i>n</i></sub>, <i>y</i><sub class=\"lower-index\">2·<i>n</i></sub>)</span> distinct, if there is such <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ 2·<i>n</i>)</span>, that <span class=\"tex-span\">(<i>p</i><sub class=\"lower-index\"><i>i</i></sub>, <i>q</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ (<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>)</span>.</p><p>As the answer can be rather large, print the remainder from dividing the answer by number <span class=\"tex-span\"><i>m</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The third line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The numbers in the lines are separated by spaces.</p><p>The last line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(2 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the single line print the remainder after dividing the answer to the problem by number <span class=\"tex-span\"><i>m</i></span>. </p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>1<br/>2<br/>7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 2<br/>2 3<br/>11<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample you can get only one sequence: <span class=\"tex-span\">(1, 1), (2, 1)</span>. </p><p>In the second sample you can get such sequences : <span class=\"tex-span\">(1, 1), (2, 2), (2, 1), (3, 2)</span>; <span class=\"tex-span\">(1, 1), (2, 1), (2, 2), (3, 2)</span>. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/272\">Codeforces Round 167 (Div. 2)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/272/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Combinatorics\">\r\n combinatorics\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1600\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='42ea0e969d88ab5961ddce4369bf3ce0'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2625\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='42ea0e969d88ab5961ddce4369bf3ce0'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2625\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script 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style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6625\" title=\"Codeforces Round #167 tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1736:1737\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/272\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/272/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/272/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/272/status\">Status</a></li>\r\n <li><a\r\n 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result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_a107c2f400483e3d3df50d7df9900a8ccb00c78b\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Dima and Two Sequences</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Little Dima has two sequences of points with integer coordinates: sequence <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\">1</sub>, 1), (<i>a</i><sub class=\"lower-index\">2</sub>, 2), ..., (<i>a</i><sub class=\"lower-index\"><i>n</i></sub>, <i>n</i>)</span> and sequence <span class=\"tex-span\">(<i>b</i><sub class=\"lower-index\">1</sub>, 1), (<i>b</i><sub class=\"lower-index\">2</sub>, 2), ..., (<i>b</i><sub class=\"lower-index\"><i>n</i></sub>, <i>n</i>)</span>.</p><p>Now Dima wants to count the number of distinct sequences of points of length <span class=\"tex-span\">2·<i>n</i></span> that can be assembled from these sequences, such that the <span class=\"tex-span\"><i>x</i></span>-coordinates of points in the assembled sequence will <span class=\"tex-font-style-bf\">not decrease</span>. Help him with that. Note that each element of the initial sequences should be used exactly once in the assembled sequence.</p><p>Dima considers two assembled sequences <span class=\"tex-span\">(<i>p</i><sub class=\"lower-index\">1</sub>, <i>q</i><sub class=\"lower-index\">1</sub>), (<i>p</i><sub class=\"lower-index\">2</sub>, <i>q</i><sub class=\"lower-index\">2</sub>), ..., (<i>p</i><sub class=\"lower-index\">2·<i>n</i></sub>, <i>q</i><sub class=\"lower-index\">2·<i>n</i></sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>), (<i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>), ..., (<i>x</i><sub class=\"lower-index\">2·<i>n</i></sub>, <i>y</i><sub class=\"lower-index\">2·<i>n</i></sub>)</span> distinct, if there is such <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ 2·<i>n</i>)</span>, that <span class=\"tex-span\">(<i>p</i><sub class=\"lower-index\"><i>i</i></sub>, <i>q</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ (<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>)</span>.</p><p>As the answer can be rather large, print the remainder from dividing the answer by number <span class=\"tex-span\"><i>m</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The third line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The numbers in the lines are separated by spaces.</p><p>The last line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(2 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the single line print the remainder after dividing the answer to the problem by number <span class=\"tex-span\"><i>m</i></span>. </p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />1<br />2<br />7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 2<br />2 3<br />11<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample you can get only one sequence: <span class=\"tex-span\">(1, 1), (2, 1)</span>. </p><p>In the second sample you can get such sequences : <span class=\"tex-span\">(1, 1), (2, 2), (2, 1), (3, 2)</span>; <span class=\"tex-span\">(1, 1), (2, 1), (2, 2), (3, 2)</span>. 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Horses"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Dima and Horses</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima came to the horse land. There are <span class=\"tex-span\"><i>n</i></span> horses living in the land. Each horse in the horse land has several enemies (enmity is a symmetric relationship). The horse land isn't very hostile, so the number of enemies of each horse is at most 3.</p><p>Right now the horse land is going through an election campaign. So the horses trusted Dima to split them into two parts. At that the horses want the following condition to hold: a horse shouldn't have more than one enemy in its party.</p><p>Help Dima split the horses into parties. Note that one of the parties can turn out to be empty.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i>, <i>m</i></span> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9286df99a4a6d23ea6b590603f389d480868e453.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> — the number of horses in the horse land and the number of enemy pairs.</p><p>Next <span class=\"tex-span\"><i>m</i></span> lines define the enemy pairs. The <span class=\"tex-span\"><i>i</i></span>-th line contains integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, which mean that horse <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is the enemy of horse <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Consider the horses indexed in some way from 1 to <span class=\"tex-span\"><i>n</i></span>. It is guaranteed that each horse has at most three enemies. No pair of enemies occurs more than once in the input.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a line, consisting of <span class=\"tex-span\"><i>n</i></span> characters: the <span class=\"tex-span\"><i>i</i></span>-th character of the line must equal \"<span class=\"tex-font-style-tt\">0</span>\", if the horse number <span class=\"tex-span\"><i>i</i></span> needs to go to the first party, otherwise this character should equal \"<span class=\"tex-font-style-tt\">1</span>\".</p><p>If there isn't a way to divide the horses as required, print <span class=\"tex-font-style-tt\">-1</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 2<br/>3 2<br/>3 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>100<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 1<br/>2 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>00<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>10 6<br/>1 2<br/>1 3<br/>1 4<br/>2 3<br/>2 4<br/>3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0110000000<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"3d47759455ff50686c97fce51571f77a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"e09ff796b44559e049aa751f6da398be96cbe0e6\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6625\" title=\"Codeforces Round #167 tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1736:1737\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/272\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/272/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/272/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/272/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/272/hacks\">Hacks</a></li>\r\n 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value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_c8ebd9a5a0c7043e053a88d26da653607798bf0b\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Dima and Horses</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima came to the horse land. There are <span class=\"tex-span\"><i>n</i></span> horses living in the land. Each horse in the horse land has several enemies (enmity is a symmetric relationship). The horse land isn't very hostile, so the number of enemies of each horse is at most 3.</p><p>Right now the horse land is going through an election campaign. So the horses trusted Dima to split them into two parts. At that the horses want the following condition to hold: a horse shouldn't have more than one enemy in its party.</p><p>Help Dima split the horses into parties. Note that one of the parties can turn out to be empty.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i>, <i>m</i></span> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9286df99a4a6d23ea6b590603f389d480868e453.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> — the number of horses in the horse land and the number of enemy pairs.</p><p>Next <span class=\"tex-span\"><i>m</i></span> lines define the enemy pairs. The <span class=\"tex-span\"><i>i</i></span>-th line contains integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, which mean that horse <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is the enemy of horse <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Consider the horses indexed in some way from 1 to <span class=\"tex-span\"><i>n</i></span>. It is guaranteed that each horse has at most three enemies. No pair of enemies occurs more than once in the input.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a line, consisting of <span class=\"tex-span\"><i>n</i></span> characters: the <span class=\"tex-span\"><i>i</i></span>-th character of the line must equal "<span class=\"tex-font-style-tt\">0</span>", if the horse number <span class=\"tex-span\"><i>i</i></span> needs to go to the first party, otherwise this character should equal "<span class=\"tex-font-style-tt\">1</span>".</p><p>If there isn't a way to divide the horses as required, print <span class=\"tex-font-style-tt\">-1</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 2<br />3 2<br />3 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>100<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 1<br />2 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>00<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>10 6<br />1 2<br />1 3<br />1 4<br />2 3<br />2 4<br />3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0110000000<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Staircase"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Dima and Staircase</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima's got a staircase that consists of <span class=\"tex-span\"><i>n</i></span> stairs. The first stair is at height <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, the second one is at <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, the last one is at <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\">1</sub> ≤ <i>a</i><sub class=\"lower-index\">2</sub> ≤ ... ≤ <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>). </p><p>Dima decided to play with the staircase, so he is throwing rectangular boxes at the staircase from above. The <span class=\"tex-span\"><i>i</i></span>-th box has width <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> and height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>. Dima throws each box vertically down on the first <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> stairs of the staircase, that is, the box covers stairs with numbers <span class=\"tex-span\">1, 2, ..., <i>w</i><sub class=\"lower-index\"><i>i</i></sub></span>. Each thrown box flies vertically down until at least one of the two following events happen:</p><ul> <li> the bottom of the box touches the top of a stair; </li><li> the bottom of the box touches the top of a box, thrown earlier. </li></ul><p>We only consider touching of the horizontal sides of stairs and boxes, at that touching with the corners isn't taken into consideration. Specifically, that implies that a box with width <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> cannot touch the stair number <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub> + 1</span>.</p><p>You are given the description of the staircase and the sequence in which Dima threw the boxes at it. For each box, determine how high the bottom of the box after landing will be. Consider a box to fall after the previous one lands.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of stairs in the staircase. The second line contains a non-decreasing sequence, consisting of <span class=\"tex-span\"><i>n</i></span> integers, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub>)</span>.</p><p>The next line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of boxes. Each of the following <span class=\"tex-span\"><i>m</i></span> lines contains a pair of integers <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub>, <i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>w</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>; 1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span> — the size of the <span class=\"tex-span\"><i>i</i></span>-th thrown box.</p><p>The numbers in the lines are separated by spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-span\"><i>m</i></span> integers — for each box the height, where the bottom of the box will be after landing. Print the answers for the boxes in the order, in which the boxes are given in the input.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in <span class=\"tex-font-style-it\">C++</span>. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>1 2 3 6 6<br/>4<br/>1 1<br/>3 1<br/>1 1<br/>4 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>3<br/>4<br/>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>1 2 3<br/>2<br/>1 1<br/>3 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>1<br/>5<br/>1 2<br/>1 10<br/>1 10<br/>1 10<br/>1 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>3<br/>13<br/>23<br/>33<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>The first sample are shown on the picture.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/26b9c4700d78041bb0da712cc0530f4b16d7ec8f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"8c50bbf940b3340a67f789dd32d33c5c\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"6707e8f7e5ee2173d5b48ab5cbe7e95277e33ff2\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='8c50bbf940b3340a67f789dd32d33c5c'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2627\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='8c50bbf940b3340a67f789dd32d33c5c'/>\r\n <input name=\"action\" type=\"hidden\" 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}\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_4e49ae10a84cf544f08df75ee601a8ed13d106a5\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Dima and Staircase</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima's got a staircase that consists of <span class=\"tex-span\"><i>n</i></span> stairs. The first stair is at height <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub></span>, the second one is at <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">2</sub></span>, the last one is at <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> (<span class=\"tex-span\">1 ≤ <i>a</i><sub class=\"lower-index\">1</sub> ≤ <i>a</i><sub class=\"lower-index\">2</sub> ≤ ... ≤ <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span>). </p><p>Dima decided to play with the staircase, so he is throwing rectangular boxes at the staircase from above. The <span class=\"tex-span\"><i>i</i></span>-th box has width <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> and height <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\"><i>i</i></sub></span>. Dima throws each box vertically down on the first <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> stairs of the staircase, that is, the box covers stairs with numbers <span class=\"tex-span\">1, 2, ..., <i>w</i><sub class=\"lower-index\"><i>i</i></sub></span>. Each thrown box flies vertically down until at least one of the two following events happen:</p><ul> <li> the bottom of the box touches the top of a stair; </li><li> the bottom of the box touches the top of a box, thrown earlier. </li></ul><p>We only consider touching of the horizontal sides of stairs and boxes, at that touching with the corners isn't taken into consideration. Specifically, that implies that a box with width <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> cannot touch the stair number <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub> + 1</span>.</p><p>You are given the description of the staircase and the sequence in which Dima threw the boxes at it. For each box, determine how high the bottom of the box after landing will be. Consider a box to fall after the previous one lands.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of stairs in the staircase. The second line contains a non-decreasing sequence, consisting of <span class=\"tex-span\"><i>n</i></span> integers, <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>a</i><sub class=\"lower-index\"><i>i</i> + 1</sub>)</span>.</p><p>The next line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(1 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span> — the number of boxes. Each of the following <span class=\"tex-span\"><i>m</i></span> lines contains a pair of integers <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub>, <i>h</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>w</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>; 1 ≤ <i>h</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span> — the size of the <span class=\"tex-span\"><i>i</i></span>-th thrown box.</p><p>The numbers in the lines are separated by spaces.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-span\"><i>m</i></span> integers — for each box the height, where the bottom of the box will be after landing. Print the answers for the boxes in the order, in which the boxes are given in the input.</p><p>Please, do not use the <span class=\"tex-font-style-tt\">%lld</span> specifier to read or write 64-bit integers in <span class=\"tex-font-style-it\">C++</span>. It is preferred to use the <span class=\"tex-font-style-tt\">cin</span>, <span class=\"tex-font-style-tt\">cout</span> streams or the <span class=\"tex-font-style-tt\">%I64d</span> specifier.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />1 2 3 6 6<br />4<br />1 1<br />3 1<br />1 1<br />4 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />3<br />4<br />6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />1 2 3<br />2<br />1 1<br />3 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />1<br />5<br />1 2<br />1 10<br />1 10<br />1 10<br />1 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />3<br />13<br />23<br />33<br /></pre></div></div></div><div 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. 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none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Two Sequences"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Dima and Two Sequences</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Little Dima has two sequences of points with integer coordinates: sequence <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\">1</sub>, 1), (<i>a</i><sub class=\"lower-index\">2</sub>, 2), ..., (<i>a</i><sub class=\"lower-index\"><i>n</i></sub>, <i>n</i>)</span> and sequence <span class=\"tex-span\">(<i>b</i><sub class=\"lower-index\">1</sub>, 1), (<i>b</i><sub class=\"lower-index\">2</sub>, 2), ..., (<i>b</i><sub class=\"lower-index\"><i>n</i></sub>, <i>n</i>)</span>.</p><p>Now Dima wants to count the number of distinct sequences of points of length <span class=\"tex-span\">2·<i>n</i></span> that can be assembled from these sequences, such that the <span class=\"tex-span\"><i>x</i></span>-coordinates of points in the assembled sequence will <span class=\"tex-font-style-bf\">not decrease</span>. Help him with that. Note that each element of the initial sequences should be used exactly once in the assembled sequence.</p><p>Dima considers two assembled sequences <span class=\"tex-span\">(<i>p</i><sub class=\"lower-index\">1</sub>, <i>q</i><sub class=\"lower-index\">1</sub>), (<i>p</i><sub class=\"lower-index\">2</sub>, <i>q</i><sub class=\"lower-index\">2</sub>), ..., (<i>p</i><sub class=\"lower-index\">2·<i>n</i></sub>, <i>q</i><sub class=\"lower-index\">2·<i>n</i></sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>), (<i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>), ..., (<i>x</i><sub class=\"lower-index\">2·<i>n</i></sub>, <i>y</i><sub class=\"lower-index\">2·<i>n</i></sub>)</span> distinct, if there is such <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ 2·<i>n</i>)</span>, that <span class=\"tex-span\">(<i>p</i><sub class=\"lower-index\"><i>i</i></sub>, <i>q</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ (<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>)</span>.</p><p>As the answer can be rather large, print the remainder from dividing the answer by number <span class=\"tex-span\"><i>m</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The third line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The numbers in the lines are separated by spaces.</p><p>The last line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(2 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the single line print the remainder after dividing the answer to the problem by number <span class=\"tex-span\"><i>m</i></span>. </p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1<br/>1<br/>2<br/>7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>1 2<br/>2 3<br/>11<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample you can get only one sequence: <span class=\"tex-span\">(1, 1), (2, 1)</span>. </p><p>In the second sample you can get such sequences : <span class=\"tex-span\">(1, 1), (2, 2), (2, 1), (3, 2)</span>; <span class=\"tex-span\">(1, 1), (2, 1), (2, 2), (3, 2)</span>. Thus, the answer is <span class=\"tex-span\">2</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"34cfcafb047f28f933b4aa747b59e66a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"6707e8f7e5ee2173d5b48ab5cbe7e95277e33ff2\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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\"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_c15faac405f3462b29c93490ef948b7df0df0fea\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Dima and Two Sequences</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Little Dima has two sequences of points with integer coordinates: sequence <span class=\"tex-span\">(<i>a</i><sub class=\"lower-index\">1</sub>, 1), (<i>a</i><sub class=\"lower-index\">2</sub>, 2), ..., (<i>a</i><sub class=\"lower-index\"><i>n</i></sub>, <i>n</i>)</span> and sequence <span class=\"tex-span\">(<i>b</i><sub class=\"lower-index\">1</sub>, 1), (<i>b</i><sub class=\"lower-index\">2</sub>, 2), ..., (<i>b</i><sub class=\"lower-index\"><i>n</i></sub>, <i>n</i>)</span>.</p><p>Now Dima wants to count the number of distinct sequences of points of length <span class=\"tex-span\">2·<i>n</i></span> that can be assembled from these sequences, such that the <span class=\"tex-span\"><i>x</i></span>-coordinates of points in the assembled sequence will <span class=\"tex-font-style-bf\">not decrease</span>. Help him with that. Note that each element of the initial sequences should be used exactly once in the assembled sequence.</p><p>Dima considers two assembled sequences <span class=\"tex-span\">(<i>p</i><sub class=\"lower-index\">1</sub>, <i>q</i><sub class=\"lower-index\">1</sub>), (<i>p</i><sub class=\"lower-index\">2</sub>, <i>q</i><sub class=\"lower-index\">2</sub>), ..., (<i>p</i><sub class=\"lower-index\">2·<i>n</i></sub>, <i>q</i><sub class=\"lower-index\">2·<i>n</i></sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>), (<i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>), ..., (<i>x</i><sub class=\"lower-index\">2·<i>n</i></sub>, <i>y</i><sub class=\"lower-index\">2·<i>n</i></sub>)</span> distinct, if there is such <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ 2·<i>n</i>)</span>, that <span class=\"tex-span\">(<i>p</i><sub class=\"lower-index\"><i>i</i></sub>, <i>q</i><sub class=\"lower-index\"><i>i</i></sub>) ≠ (<i>x</i><sub class=\"lower-index\"><i>i</i></sub>, <i>y</i><sub class=\"lower-index\"><i>i</i></sub>)</span>.</p><p>As the answer can be rather large, print the remainder from dividing the answer by number <span class=\"tex-span\"><i>m</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 10<sup class=\"upper-index\">5</sup>)</span>. The second line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\">1</sub>, <i>a</i><sub class=\"lower-index\">2</sub>, ..., <i>a</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The third line contains <span class=\"tex-span\"><i>n</i></span> integers <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\">1</sub>, <i>b</i><sub class=\"lower-index\">2</sub>, ..., <i>b</i><sub class=\"lower-index\"><i>n</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The numbers in the lines are separated by spaces.</p><p>The last line contains integer <span class=\"tex-span\"><i>m</i></span> <span class=\"tex-span\">(2 ≤ <i>m</i> ≤ 10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the single line print the remainder after dividing the answer to the problem by number <span class=\"tex-span\"><i>m</i></span>. </p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1<br />1<br />2<br />7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />1 2<br />2 3<br />11<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample you can get only one sequence: <span class=\"tex-span\">(1, 1), (2, 1)</span>. </p><p>In the second sample you can get such sequences : <span class=\"tex-span\">(1, 1), (2, 2), (2, 1), (3, 2)</span>; <span class=\"tex-span\">(1, 1), (2, 1), (2, 2), (3, 2)</span>. 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. 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none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Horses"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Dima and Horses</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima came to the horse land. There are <span class=\"tex-span\"><i>n</i></span> horses living in the land. Each horse in the horse land has several enemies (enmity is a symmetric relationship). The horse land isn't very hostile, so the number of enemies of each horse is at most 3.</p><p>Right now the horse land is going through an election campaign. So the horses trusted Dima to split them into two parts. At that the horses want the following condition to hold: a horse shouldn't have more than one enemy in its party.</p><p>Help Dima split the horses into parties. Note that one of the parties can turn out to be empty.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i>, <i>m</i></span> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9286df99a4a6d23ea6b590603f389d480868e453.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> — the number of horses in the horse land and the number of enemy pairs.</p><p>Next <span class=\"tex-span\"><i>m</i></span> lines define the enemy pairs. The <span class=\"tex-span\"><i>i</i></span>-th line contains integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, which mean that horse <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is the enemy of horse <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Consider the horses indexed in some way from 1 to <span class=\"tex-span\"><i>n</i></span>. It is guaranteed that each horse has at most three enemies. No pair of enemies occurs more than once in the input.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a line, consisting of <span class=\"tex-span\"><i>n</i></span> characters: the <span class=\"tex-span\"><i>i</i></span>-th character of the line must equal \"<span class=\"tex-font-style-tt\">0</span>\", if the horse number <span class=\"tex-span\"><i>i</i></span> needs to go to the first party, otherwise this character should equal \"<span class=\"tex-font-style-tt\">1</span>\".</p><p>If there isn't a way to divide the horses as required, print <span class=\"tex-font-style-tt\">-1</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 2<br/>3 2<br/>3 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>100<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 1<br/>2 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>00<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>10 6<br/>1 2<br/>1 3<br/>1 4<br/>2 3<br/>2 4<br/>3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0110000000<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"b91010593aeb176694c3c7a74832513e\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"6707e8f7e5ee2173d5b48ab5cbe7e95277e33ff2\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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|| c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_fbc44c0adbfd2e2b58565d48827d84b11c76a46f\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Dima and Horses</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima came to the horse land. There are <span class=\"tex-span\"><i>n</i></span> horses living in the land. Each horse in the horse land has several enemies (enmity is a symmetric relationship). The horse land isn't very hostile, so the number of enemies of each horse is at most 3.</p><p>Right now the horse land is going through an election campaign. So the horses trusted Dima to split them into two parts. At that the horses want the following condition to hold: a horse shouldn't have more than one enemy in its party.</p><p>Help Dima split the horses into parties. Note that one of the parties can turn out to be empty.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i>, <i>m</i></span> <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/9286df99a4a6d23ea6b590603f389d480868e453.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> — the number of horses in the horse land and the number of enemy pairs.</p><p>Next <span class=\"tex-span\"><i>m</i></span> lines define the enemy pairs. The <span class=\"tex-span\"><i>i</i></span>-th line contains integers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\">(1 ≤ <i>a</i><sub class=\"lower-index\"><i>i</i></sub>, <i>b</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>n</i>; <i>a</i><sub class=\"lower-index\"><i>i</i></sub> ≠ <i>b</i><sub class=\"lower-index\"><i>i</i></sub>)</span>, which mean that horse <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is the enemy of horse <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span>.</p><p>Consider the horses indexed in some way from 1 to <span class=\"tex-span\"><i>n</i></span>. It is guaranteed that each horse has at most three enemies. No pair of enemies occurs more than once in the input.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print a line, consisting of <span class=\"tex-span\"><i>n</i></span> characters: the <span class=\"tex-span\"><i>i</i></span>-th character of the line must equal "<span class=\"tex-font-style-tt\">0</span>", if the horse number <span class=\"tex-span\"><i>i</i></span> needs to go to the first party, otherwise this character should equal "<span class=\"tex-font-style-tt\">1</span>".</p><p>If there isn't a way to divide the horses as required, print <span class=\"tex-font-style-tt\">-1</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 2<br />3 2<br />3 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>100<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 1<br />2 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>00<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>10 6<br />1 2<br />1 3<br />1 4<br />2 3<br />2 4<br />3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0110000000<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:53:38</span><br/><a href=\"/contestRegistration/1877\">Register now »</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 — Final 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style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 — Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ㅅ´ ˘ `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Figure"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Dima and Figure</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima loves making pictures on a piece of squared paper. And yet more than that Dima loves the pictures that depict one of his favorite figures. </p><p>A piece of squared paper of size <span class=\"tex-span\"><i>n</i> × <i>m</i></span> is represented by a table, consisting of <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>m</i></span> columns. All squares are white on blank squared paper. Dima defines a <span class=\"tex-font-style-it\">picture</span> as an image on a blank piece of paper, obtained by painting some squares black.</p><p>The picture portrays one of Dima's favorite figures, if the following conditions hold:</p><ul> <li> The picture contains at least one painted cell; </li><li> All painted cells form a connected set, that is, you can get from any painted cell to any other one (you can move from one cell to a side-adjacent one); </li><li> The minimum number of moves needed to go from the painted cell at coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span> to the painted cell at coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>)</span>, moving only through the colored cells, equals <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>x</i><sub class=\"lower-index\">2</sub>| + |<i>y</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">2</sub>|</span>. </li></ul><p>Now Dima is wondering: how many paintings are on an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> piece of paper, that depict one of his favorite figures? Count this number modulo <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> — the sizes of the piece of paper <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 150)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the remainder after dividing the answer to the problem by number <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>13<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>571<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"3bf8de2561921c566f5d7997e6411df8\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"6707e8f7e5ee2173d5b48ab5cbe7e95277e33ff2\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2400\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='3bf8de2561921c566f5d7997e6411df8'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"2630\"/>\r\n <input name=\"tagName\" type=\"hidden\" 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{\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6677\" title=\"Codeforces Round #167\" target=\"_blank\">Codeforces Round #167</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1492:1493\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/6625\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1507\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/273\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/273/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/273/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/273/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/273/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/273/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/273/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/273/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 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\"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_9134f6ef5c8cc908eb8438a9b48c1a14bcecb8ba\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Dima and Figure</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima loves making pictures on a piece of squared paper. And yet more than that Dima loves the pictures that depict one of his favorite figures. </p><p>A piece of squared paper of size <span class=\"tex-span\"><i>n</i> × <i>m</i></span> is represented by a table, consisting of <span class=\"tex-span\"><i>n</i></span> rows and <span class=\"tex-span\"><i>m</i></span> columns. All squares are white on blank squared paper. Dima defines a <span class=\"tex-font-style-it\">picture</span> as an image on a blank piece of paper, obtained by painting some squares black.</p><p>The picture portrays one of Dima's favorite figures, if the following conditions hold:</p><ul> <li> The picture contains at least one painted cell; </li><li> All painted cells form a connected set, that is, you can get from any painted cell to any other one (you can move from one cell to a side-adjacent one); </li><li> The minimum number of moves needed to go from the painted cell at coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>, <i>y</i><sub class=\"lower-index\">1</sub>)</span> to the painted cell at coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">2</sub>, <i>y</i><sub class=\"lower-index\">2</sub>)</span>, moving only through the colored cells, equals <span class=\"tex-span\">|<i>x</i><sub class=\"lower-index\">1</sub> - <i>x</i><sub class=\"lower-index\">2</sub>| + |<i>y</i><sub class=\"lower-index\">1</sub> - <i>y</i><sub class=\"lower-index\">2</sub>|</span>. </li></ul><p>Now Dima is wondering: how many paintings are on an <span class=\"tex-span\"><i>n</i> × <i>m</i></span> piece of paper, that depict one of his favorite figures? Count this number modulo <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> — the sizes of the piece of paper <span class=\"tex-span\">(1 ≤ <i>n</i>, <i>m</i> ≤ 150)</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the remainder after dividing the answer to the problem by number <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>13<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>571<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='910c361ed8fb95c00af76d7c65ecc83d'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/Sereja\">Sereja</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Sereja\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Sereja\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Sereja\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Sereja\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Sereja\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Sereja\" style=\"text-decoration:none;color:black !important;\">Sereja's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"6674\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/6625\"> <p>Codeforces Round #167 tutorial</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a>,\r\n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"/contest/272/problem/A\" title=\"Codeforces Round 167 (Div. 2)\">272A - Dima and Friends</a> </p><p>We will bruteforce number of fingers that will be show Dima, then if total sum of fingers = 1 modulo (n+1), Dima will clean the room. So we should increase answer if the remaining part after division by (n+1) is not 1. </p><p><a href=\"/contest/272/problem/B\" title=\"Codeforces Round 167 (Div. 2)\">272B - Dima and Sequence</a><br />First of all — f(i) is number of ones in binary presentation of number. We will repair all numbers to functions of them. Now we have to find number of pairs of equal numbers. Lets Q[i] — number of numbers with i bits, the answer will be sum of values Q[i]*(Q[i]-1)/2 for all i.</p><p><a href=\"/contest/273/problem/A\" title=\"Codeforces Round 167 (Div. 1)\">273A - Dima and Staircase</a><br />Lets L will be the answer after last block, last block was (w1, h1), next block is (w2, h2). Next answer will be max(L+h1, A[w2]), where A — given array. At the beggining we can suppose that L = 0, w1 = 0, h1 = 0.</p><p><a href=\"/contest/273/problem/B\" title=\"Codeforces Round 167 (Div. 1)\">273B - Dima and Two Sequences</a><br />Not hard to understand that answer will be (number of numbers with first coordinate = 1)! * (number of numbers with first coordinate = 2)! * ... * (number of numbers with first coordinate = 10^9)!/(2^(number of such i = 1..n, that Ai=Bi)). The only problem was to divide number with non prime modulo, it can be easely done if we will count number of prime mulpiplies=2 in all factorials. Then we can simply substract number that we need and multiply answer for some power of 2.</p><p><a href=\"/contest/273/problem/C\" title=\"Codeforces Round 167 (Div. 1)\">273C - Dima and Horses</a><br />Not hard to understand that we have undirected graph. Lets color all vetexes in one color. Then we will find some vertex that is incorrect. We will change color of this vertex, and repeat our search, while it is possible. After every move number of bad edges will be decrease by 1 or 2, so our cycle will end in not more then M operations. So solutions always exists and we need to change some vertex not more then M times, so we will take queue of bad vertexes and simply make all operations of changes. </p><p><a href=\"/contest/273/problem/D\" title=\"Codeforces Round 167 (Div. 1)\">273D - Dima and Figure</a><br />Good picture is connected figure that saticfy next condition: most left coordinates in every row of figure vere we have some cells will be almost-ternary, we have the same situation with right side, but here we have another sign. So it is not hard to write dp[i][j1][j2][m1][m2] numbr of figures printed of field size i*m, where last row contain all cells from j1 to j2, the most left coordinate will be m1, the most right coordinate will be m2. But it is not enough. We have to rewrite it in way that m1 will mean — was there some rows j and j+1 that most left coordinate if row j is bigger then most left coordinate in j+1. So now it is not hard to write solution with coplexity O(n*m*m*m*m). But we should optimize transfer to O(1), is can be done using precalculations of sums on some rectangels. </p><p><a href=\"/contest/273/problem/E\" title=\"Codeforces Round 167 (Div. 1)\">273E - Dima and Game</a><br />will be added soon.</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/272\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 2)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/273\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 167 (Div. 1)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1981-6674\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1981\",\n blogEntryId: \"6625\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=round\" class=\"tag notice\" style=\"text-decoration: none;\">round</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=167\" class=\"tag notice\" style=\"text-decoration: none;\">167</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+12</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-6674\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Sereja\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Sereja\">\n Sereja\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Feb/07/2013 06:04\">11 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/6625#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/6625#comments\">\n 49\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"6684\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (41)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122562\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 12:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122562\" href=\"?#comment-122562\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122562\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122562\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122562\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122562 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122562 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122562\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122633\" commentParentId=\"122562\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/_TMB_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/44683/avatar/195450c4cfd20886.jpg'/> </a>\n <div><a href=\"/profile/_TMB_\" title=\"Candidate Master _TMB_\" class=\"rated-user user-violet\">_TMB_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122633\" href=\"?#comment-122633\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122562\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122633\" revisionCount=\"6\" revision=\"6\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">6</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122633\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"44683\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122633\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>[Deleted]</p><p><strong>Sorry, because of my browser's error.</strong></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122633 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122633 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122633\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122582\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Salamander\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73625/avatar/6391b98822e86ed5.jpg'/> </a>\n <div><a href=\"/profile/Salamander\" title=\"Specialist Salamander\" class=\"rated-user user-cyan\">Salamander</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122582\" href=\"?#comment-122582\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122582\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"73625\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122582\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In solve D(div2), why we divided by 2^(number of such i = 1..n,that Ai=Bi)? I don't understand, please proof.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122582 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122582 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122582\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122588\" commentParentId=\"122582\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/zzxchavo\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/54225/avatar/ee71f13bfd560295.jpg'/> </a>\n <div><a href=\"/profile/zzxchavo\" title=\"Expert zzxchavo\" class=\"rated-user user-blue\">zzxchavo</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 14:33\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122588\" href=\"?#comment-122588\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122582\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122588\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"54225\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122588\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Consider the influence of the position of pair(Ai,i) and pair(Bi,i). In one sequence,if we change the position of (Ai,i) and (Bi,i),that will not form a new sequence. But when we solve the problem, what we are calculating is that all different positions for all pairs with same x-coordinate. And that contains the different positions of Ai and Bi. So we divide the answer with 2, because (Ai,i) and (Bi,i) will lead to 2 different answer, but in the problem they should be considered to be 1. For all different Ai==Bi, we divide the answer with 2^k where k is the number of pairs with Ai==Bi.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122588 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122588 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122588\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122611\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/matrix\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/matrix\" title=\"Master matrix\" class=\"rated-user user-orange\">matrix</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 18:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122611\" href=\"?#comment-122611\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122611\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"16572\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122611\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It seems there is a mistake in posting tutorial. English version of tutorial is TopCoder SRM announcement and the post itself is for 8 days ago!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122611 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122611 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122611\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122622\" commentParentId=\"122611\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SiegHeil1488\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/SiegHeil1488\" title=\"Specialist SiegHeil1488\" class=\"rated-user user-cyan\">SiegHeil1488</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:16\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122622\" href=\"?#comment-122622\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122611\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122622\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-24\"\r\n data-commentUserId=\"82275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-24</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122622\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Nobody cares</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122622 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122622 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122622\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122634\" commentParentId=\"122622\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:45\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122634\" href=\"?#comment-122634\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122622\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122634\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122634\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>It was little mistake, sorry.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122634 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122634 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122634\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122618\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/TMandzu\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/12533/avatar/de6b51864896a39b.jpg'/> </a>\n <div><a href=\"/profile/TMandzu\" title=\"Candidate Master TMandzu\" class=\"rated-user user-violet\">TMandzu</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:14\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122618\" href=\"?#comment-122618\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122618\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"17\"\r\n data-commentUserId=\"12533\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+17</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122618\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I expected more detailed tutorial ...</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122618 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122618 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122618\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122630\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 19:29\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122630\" href=\"?#comment-122630\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122630\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"6\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122630\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the problem E(div 2), I want to know why it will operate at most M times?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122630 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122630 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122630\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122749\" commentParentId=\"122630\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/byijie\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/byijie\" title=\"Specialist byijie\" class=\"rated-user user-cyan\">byijie</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 07:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122749\" href=\"?#comment-122749\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122630\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122749\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122749\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"60316\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122749\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think DFS can explain it more easily.This solution is like magnetic repulsion.consider that there are two sets marked S1 and S2(at first S2 is empty),we pick one element from S1 that has more than one enemy in S1,then put it in S2,so bad edge will decrease,but in S2 maybe increase some bad edges and cause some bad elements,so we pick out these bad elements and put them into S1,and repeat this way. If there is a answer then each time the bad edges are decrease,and we can find a stable state.But i don't know how to prove that there must exist one answer.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122749 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122749 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122749\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123021\" commentParentId=\"122749\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 09:06\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123021\" href=\"?#comment-123021\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122749\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123021\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123021\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>As you said, each time bad edges will decrease. If at some point, you cannot find a vertex to fix, then the solution is found. If not, you can always find a vertex to fix and the number of bad edges will decrease. The total number of bad edges is finite, therefore the process cannot go infinitely, cause each time the number of bad edges decrease by 1 or 2 or 3,(This is ensured by each horse having at most 3 enemies, so if a horse have more than 1 enemies, it will have 1 or 0 enemies in the other party) and the total number of bad edges cannot go below zero. Therefore the process will end and a solution will come.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123021 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123021 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123021\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123027\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yunfanGetStart\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yunfanGetStart\" title=\"Expert yunfanGetStart\" class=\"rated-user user-blue\">yunfanGetStart</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 12:11\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123027\" href=\"?#comment-123027\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123027\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"33811\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123027\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks to <a class=\"rated-user user-blue\" href=\"/profile/byijie\" title=\"Expert byijie\">byijie</a> and <a class=\"rated-user user-blue\" href=\"/profile/Bobgy\" title=\"Expert Bobgy\">Bobgy</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123027 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123027 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123027\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123032\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/18/2013 14:12\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123032\" href=\"?#comment-123032\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123032\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123032\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>no problem</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123032 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123032 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123032\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124102\" commentParentId=\"123027\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124102\" href=\"?#comment-124102\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123027\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124102\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124102\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124102 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124102 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124102\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124101\" commentParentId=\"123021\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/PeterNaut\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/PeterNaut\" title=\"Expert PeterNaut\" class=\"rated-user user-blue\">PeterNaut</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 07:28\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124101\" href=\"?#comment-124101\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123021\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124101\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"82248\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124101\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What is meant by "bad edge"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124101 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124101 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124101\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"124104\" commentParentId=\"124101\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/27/2013 08:08\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-124104\" href=\"?#comment-124104\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-124101\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"124104\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-124104\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>an edge that is connecting two vertex in the same set.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-124104 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-124104 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-124104\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122635\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/bekzhan29\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/14217/avatar/c6e361cec763cbf0.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/bekzhan29\" title=\"Grandmaster bekzhan29\" class=\"rated-user user-red\">bekzhan29</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 20:32\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122635\" href=\"?#comment-122635\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122635\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122635\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"7\"\r\n data-commentUserId=\"14217\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+7</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122635\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>C(div. 1). "Then we will find some vertex that is incorrect." what does it mean? What do you mean by saying "incorrect"?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122635 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122635 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122635\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122645\" commentParentId=\"122635\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Miras321\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/50098/avatar/4f630d5cdb14e6a8.jpg'/> </a>\n <div><a href=\"/profile/Miras321\" title=\"Expert Miras321\" class=\"rated-user user-blue\">Miras321</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/14/2013 22:31\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122645\" href=\"?#comment-122645\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122635\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122645\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"50098\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122645\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Vertex (horse) is incorrect, if it has more than one enemy in other party.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122645 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122645 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122645\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122668\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 11:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122668\" href=\"?#comment-122668\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122668\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122668\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122668\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>How can we solve problem "Dima and Horses" by 2-SAT method? Thanks Actually, I don't know method 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122668 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122668 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122668\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122715\" commentParentId=\"122668\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Edvard\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/345/avatar/b5fe685881b67116.jpg'/> </a>\n <div><a href=\"/profile/Edvard\" title=\"Candidate Master Edvard\" class=\"rated-user user-violet\">Edvard</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 18:44\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122715\" href=\"?#comment-122715\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122668\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122715\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"345\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122715\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I don't sure that this problem can be solved by 2-SAT.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122715 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122715 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122715\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122679\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 13:07\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122679\" href=\"?#comment-122679\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122679\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122679\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Isn't Problem D for Division 1 is supposed to solved in O(M*N*N) time? Don't need to keep track of m1 and m2, just keep that whether m1 < j1 or not and whether m2 > j2 or not, that is whether it has reached its leftmost cell and its rightmost cell.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122679 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122679 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122679\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122725\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 21:55\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122725\" href=\"?#comment-122725\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122725\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122725\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Никак не пойму, как все-таки в D делать переход за O(1)?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122725 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122725 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122725\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122731\" commentParentId=\"122725\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 22:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122731\" href=\"?#comment-122731\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122725\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122731\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122731\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>а вы поняли по каким правилам dp строится ?</p><p>у меня идея подобная была, я трактовал m1 и m2 {0,1} — можно ли след-ий столбец расширить вниз/вверх соотв-но. здесь тоже так?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122731 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122731 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122731\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122733\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:10\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122733\" href=\"?#comment-122733\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122733\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122733\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Я мало что понял из разбора, но моем в моем "решении" за O(N^5) все так. И для перехода из состояния у меня нужно значение динамики в этом состоянии добавить к нескольким прямоугольникам на следующем "слое". Вот как-то надо сделать это быстро. Видимо загадочное "precalculations of sums on some rectangels" — это как раз то что нужно.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122733 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122733 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122733\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122736\" commentParentId=\"122733\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hydrastuff\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/275/avatar/ff280c3ff302e9d3.jpg'/> </a>\n <div><a href=\"/profile/hydrastuff\" title=\"Master hydrastuff\" class=\"rated-user user-orange\">hydrastuff</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:38\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122736\" href=\"?#comment-122736\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122733\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122736\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"8\"\r\n data-commentUserId=\"275\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+8</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122736\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Лучше сделать переход дп не вперед, а назад, тогда перед переходами делаешь прекальк частичных сумм для текущего слоя, чтобы потом можно взять сумму любой подматрицы.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122736 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122736 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122736\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122738\" commentParentId=\"122736\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Hohol\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/198/avatar/9feafb975d9089d3.jpg'/> </a>\n <div><a href=\"/profile/Hohol\" title=\"Candidate Master Hohol\" class=\"rated-user user-violet\">Hohol</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2013 23:53\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122738\" href=\"?#comment-122738\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122736\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122738\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"198\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122738\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Точно, спасибо.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122738 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122738 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122738\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122748\" commentParentId=\"122731\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 06:09\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122748\" href=\"?#comment-122748\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122731\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122748\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122748\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122748\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>create an array a[M][2][2][N+1][N+1]. a[i][k1][k2][j1][j2] stands for number of figures with last row i and last row has cells from j1 to j2 and k1 is 0 if j1 <= m1 else 1 and k2 is 0 if j2 >= m2 else 1. Then</p><p>a[i][0][0][j1][j2] = a[i][0][0][j1+1][j2]+a[i][0][0][j1][j2-1]-a[i][0][0][j1+1][j2-1]+a[i-1][0][0][j1][j2].</p><p>a[i][0][1][j1][j2] = a[i][0][1][j1+1][j2]+a[i][0][1][j1][j2+1]-a[i][0][1][j1+1][j2+1]+a[i-1][0][1][j1][j2]+a[i-1][0][0][j1][j2+1].</p><p>a[i][1][0][j1][j2] is similar with a[i][0][1][j1][j2].</p><p>a[i][1][1][j1][j2] = a[i][1][1][j1-1][j2]+a[i][1][1][j1][j2+1]-a[i][1][1][j1-1][j2+1]+a[i-1][1][1][j1][j2]+a[i-1][0][0][j1-1][j2+1]+a[i-1][0][1][j1-1][j2]+a[i-1][1][0][j1][j2+1].</p><p>Note that if you use bottom up dp and do it in correct order you can actually omit the i and only use dp array of a[2][2][N+1][N+1]. So time complexity O(M*N*N) and memory space O(N*N).</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122748 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122748 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122748\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130898\" commentParentId=\"122748\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 18:34\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130898\" href=\"?#comment-130898\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122748\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130898\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130898\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>what's the meaning of m1 and m2?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130898 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130898 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130898\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130949\" commentParentId=\"130898\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/forget\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/forget\" title=\"Master forget\" class=\"rated-user user-orange\">forget</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 01:33\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130949\" href=\"?#comment-130949\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130898\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130949\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"77824\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130949\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the most left and right coordinates of the figure</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130949 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130949 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130949\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130964\" commentParentId=\"130949\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/22/2013 12:47\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130964\" href=\"?#comment-130964\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-130949\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130964\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130964\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>thanks,then how should I initialize the array a's state?I think I am not good at dynamic programming.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130964 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130964 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130964\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122753\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/aitzhan.askar\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/42611/avatar/a828d2bab12d1fcc.jpg'/> </a>\n <div><a href=\"/profile/aitzhan.askar\" title=\"Expert aitzhan.askar\" class=\"rated-user user-blue\">aitzhan.askar</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/16/2013 08:15\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122753\" href=\"?#comment-122753\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"122753\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"122753\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"4\"\r\n data-commentUserId=\"42611\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+4</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122753\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Так когда будет разбор на русском, я заждалься</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122753 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122753 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122753\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"122930\" commentParentId=\"122753\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rap_Promoter\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60304/avatar/7620d17762570cea.jpg'/> </a>\n <div><a href=\"/profile/Rap_Promoter\" title=\"Specialist Rap_Promoter\" class=\"rated-user user-cyan\">Rap_Promoter</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/17/2013 13:51\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-122930\" href=\"?#comment-122930\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-122753\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"122930\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"27\"\r\n data-commentUserId=\"60304\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+27</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-122930\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ждать нечего — на английском разбор напоминает конспект разбора от <a class=\"rated-user user-red\" href=\"/profile/Burunduk1\" title=\"Grandmaster Burunduk1\">Burunduk1</a> на каком-то чемпионате матмеха<img alt=\" \" src=\"/predownloaded/e8/40/e8400292f87385136f69df3d82aa2cf9b700c967.jpg\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-122930 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-122930 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-122930\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123170\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/i2013\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/i2013\" title=\"Specialist i2013\" class=\"rated-user user-cyan\">i2013</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 11:54\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123170\" href=\"?#comment-123170\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123170\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"86928\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123170\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can Problem Setter post the solution of problem "Dima and Game"? Thank you so much.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123170 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123170 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123170\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123202\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Bobgy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/53536/avatar/79d4afef1239a435.jpg'/> </a>\n <div><a href=\"/profile/Bobgy\" title=\"Master Bobgy\" class=\"rated-user user-orange\">Bobgy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/20/2013 18:22\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123202\" href=\"?#comment-123202\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123202\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"53536\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123202\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>ya, I'm waiting for it too.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123202 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123202 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123202\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"123328\" commentParentId=\"123170\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Sereja\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Sereja\" title=\"Master Sereja\" class=\"rated-user user-orange\">Sereja</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/21/2013 02:01\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-123328\" href=\"?#comment-123328\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-123170\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"123328\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"5896\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-123328\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I will post it little bit later, sorry for so long delay.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-123328 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-123328 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-123328\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"130889\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/SaberLily\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/98310/avatar/45ee8d6e25ace22e.jpg'/> </a>\n <div><a href=\"/profile/SaberLily\" title=\"Expert SaberLily\" class=\"rated-user user-blue\">SaberLily</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/21/2013 17:39\">10 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-130889\" href=\"?#comment-130889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"130889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"98310\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-130889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>the tutorial is too simple,I want more details.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-130889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-130889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-130889\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216575\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/cong741\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/221406/avatar/1656d65c41af4fa0.jpg'/> </a>\n <div><a href=\"/profile/cong741\" title=\"Expert cong741\" class=\"rated-user user-blue\">cong741</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 14:47\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216575\" href=\"?#comment-216575\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216575\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"221406\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216575\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>In the problem "Dima and Horses",why does this problem always can be worked out,i means never have the answer with -1.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216575 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216575 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216575\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"216577\" commentParentId=\"216575\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Rubanenko\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2366/avatar/1f1679364db3ac08.jpg'/> </a>\n <div><a href=\"/profile/Rubanenko\" title=\"Master Rubanenko\" class=\"rated-user user-orange\">Rubanenko</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/06/2015 15:08\">9 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-216577\" href=\"?#comment-216577\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-216575\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"216577\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2366\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-216577\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If there is at least one unsatisfied vertex, then it can be moved to another group and the overall number of conflicts is decreased(otherwise we are done). Problem is obviously solved when the number of conflicts is zero. Since we can decrease the number of conflicts whenever the problem is not yet solved, then we simply do it. One day the process will finish because the initial number of conflicts is finite. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-216577 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-216577 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-216577\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"278761\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Anu1112\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/60021/avatar/4db14fa280748aac.jpg'/> </a>\n <div><a href=\"/profile/Anu1112\" title=\"Specialist Anu1112\" class=\"rated-user user-cyan\">Anu1112</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/15/2016 10:49\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-278761\" href=\"?#comment-278761\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"278761\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"278761\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"60021\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-278761\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>273E — Dima and Game . please give this problem tutorial . <a class=\"rated-user user-orange\" href=\"/profile/Sereja\" title=\"Master Sereja\">Sereja</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-278761 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-278761 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-278761\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"631974\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/jeqcho\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/845166/avatar/4ac7d48e4acf8d39.jpg'/> </a>\n <div><a href=\"/profile/jeqcho\" title=\"Expert jeqcho\" class=\"rated-user user-blue\">jeqcho</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/29/2020 09:26\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-631974\" href=\"?#comment-631974\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"631974\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"845166\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-631974\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>For 273A/272C (Div 2 C), the general case when blocks can fall from any position (not just 0) can be solved using lazy propagation of segment tree (for range max update and range max query) in $$$O(m\\cdot \\log n)$$$. See my submission <a href=\"/contest/272/submission/81852819\" title=\"Submission 81852819 by jeqcho\">81852819</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-631974 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-631974 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-631974\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"1004186\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/deepakyadav123\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2142181/avatar/516e1a78972428f2.jpg'/> </a>\n <div><a href=\"/profile/deepakyadav123\" title=\"Newbie deepakyadav123\" class=\"rated-user user-gray\">deepakyadav123</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/12/2023 17:07\">8 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-1004186\" href=\"?#comment-1004186\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"1004186\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2142181\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-1004186\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>There is problem in a question that answer different from inputeed test case in computer , which leads to give error WA </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-1004186 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-1004186 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Dima and Game"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Dima and Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima and Anya love playing different games. Now Dima has imagined a new game that he wants to play with Anya.</p><p>Dima writes <span class=\"tex-span\"><i>n</i></span> pairs of integers on a piece of paper <span class=\"tex-span\">(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub>)</span> <span class=\"tex-span\">(1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> < <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>p</i>)</span>. Then players take turns. On his turn the player can do the following actions:</p><ol> <li> choose the number of the pair <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span>, such that <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub> - <i>l</i><sub class=\"lower-index\"><i>i</i></sub> > 2</span>; </li><li> replace pair number <span class=\"tex-span\"><i>i</i></span> by pair <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/165e2666291c061e90369a86105632c3b551f237.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> or by pair <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4756eda794b8f0bf8cf2cc9f6f2cc19c194b35b7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/>. Notation <span class=\"tex-span\">⌊<i>x</i>⌋</span> means rounding down to the closest integer. </li></ol><p>The player who can't make a move loses.</p><p>Of course, Dima wants Anya, who will move first, to win. That's why Dima should write out such <span class=\"tex-span\"><i>n</i></span> pairs of integers <span class=\"tex-span\">(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub>)</span> <span class=\"tex-span\">(1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> < <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>p</i>)</span>, that if both players play optimally well, the first one wins. Count the number of ways in which Dima can do it. Print the remainder after dividing the answer by number <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p><p>Two ways are considered distinct, if the <span class=\"tex-font-style-bf\">ordered</span> sequences of the written pairs are distinct.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>p</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 1000, 1 ≤ <i>p</i> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The numbers are separated by a single space.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the remainder after dividing the answer to the problem by number <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>520<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>100 1000<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>269568947<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"e0614bce393e6cfc4c74e0bedb4bd7a6\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"6707e8f7e5ee2173d5b48ab5cbe7e95277e33ff2\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/273\">Codeforces Round 167 (Div. 1)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='e0614bce393e6cfc4c74e0bedb4bd7a6'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/273/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/6677\" title=\"Codeforces Round #167\" target=\"_blank\">Codeforces Round #167</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1492:1493\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"https://codeforces.com/blog/entry/6625\" title=\"Tutorial\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"1507\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/273\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/273/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/273/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/273/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/273/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/273/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/273/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/273/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox 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|| c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_eb185527fad379ca03d9afb502505fd1671bfb81\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Dima and Game</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Dima and Anya love playing different games. Now Dima has imagined a new game that he wants to play with Anya.</p><p>Dima writes <span class=\"tex-span\"><i>n</i></span> pairs of integers on a piece of paper <span class=\"tex-span\">(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub>)</span> <span class=\"tex-span\">(1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> < <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>p</i>)</span>. Then players take turns. On his turn the player can do the following actions:</p><ol> <li> choose the number of the pair <span class=\"tex-span\"><i>i</i></span> <span class=\"tex-span\">(1 ≤ <i>i</i> ≤ <i>n</i>)</span>, such that <span class=\"tex-span\"><i>r</i><sub class=\"lower-index\"><i>i</i></sub> - <i>l</i><sub class=\"lower-index\"><i>i</i></sub> > 2</span>; </li><li> replace pair number <span class=\"tex-span\"><i>i</i></span> by pair <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/165e2666291c061e90369a86105632c3b551f237.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> or by pair <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/4756eda794b8f0bf8cf2cc9f6f2cc19c194b35b7.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Notation <span class=\"tex-span\">⌊<i>x</i>⌋</span> means rounding down to the closest integer. </li></ol><p>The player who can't make a move loses.</p><p>Of course, Dima wants Anya, who will move first, to win. That's why Dima should write out such <span class=\"tex-span\"><i>n</i></span> pairs of integers <span class=\"tex-span\">(<i>l</i><sub class=\"lower-index\"><i>i</i></sub>, <i>r</i><sub class=\"lower-index\"><i>i</i></sub>)</span> <span class=\"tex-span\">(1 ≤ <i>l</i><sub class=\"lower-index\"><i>i</i></sub> < <i>r</i><sub class=\"lower-index\"><i>i</i></sub> ≤ <i>p</i>)</span>, that if both players play optimally well, the first one wins. Count the number of ways in which Dima can do it. Print the remainder after dividing the answer by number <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p><p>Two ways are considered distinct, if the <span class=\"tex-font-style-bf\">ordered</span> sequences of the written pairs are distinct.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>p</i></span> <span class=\"tex-span\">(1 ≤ <i>n</i> ≤ 1000, 1 ≤ <i>p</i> ≤ 10<sup class=\"upper-index\">9</sup>)</span>. The numbers are separated by a single space.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In a single line print the remainder after dividing the answer to the problem by number <span class=\"tex-span\">1000000007 (10<sup class=\"upper-index\">9</sup> + 7)</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>520<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>100 1000<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>269568947<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n 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